Aneurysmal Bone Cyst of the Pelvis: a single-center study of 17 cases

Aneurysmal Bone Cyst of the Pelvis: a single-center study of 17 cases | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Aneurysmal Bone Cyst of the Pelvis: a single-center study of 17 cases Niklas Deventer, Tymoteusz Budny, Georg Gosheger, Marieke Vaal, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1401862/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract BACKGROUND: The aneurysmal bone cyst (ABC) is a benign, but locally aggressive cystic lesion of the bone. It usually occurs in the metaphysis of long bones of adolescents and young adults but can also affect the pelvis. METHODS: This single-center study is a retrospective review of 17 patients with primary ABCs of the pelvis. The patients were treated surgically, by polidocanol instillation and, in selected cases, transarterial embolization. RESULTS: 17 patients with the diagnosis of a primary ABC of the pelvis were included in the study. Six patients were male (35.3%) and eleven patients female (64.7%); the mean age was 17.6 (9-49) years. The mean follow-up time was 50.2 months (12-136 months). The most common location of manifestation was the pubis (6; 35.3%), followed by the ilium (6; 35.3%), the sacrum (3; 17.6%) and the ischium (2; 11.8%). Eight patients were treated by intralesional curettage with the use of adjuvants, one patient by marginal resection, seven by sequential instillation of polidocanol and one patient by simple observation. Five patients received an additional transarterial embolization. After intralesional curettage local recurrence was detected in 4/8 cases (50%). After instillation therapy six patients (85.7%) had a stable disease without recurrence, only one patient (14.3%) had a persistent disease with need of additional treatment and was therefore converted to intralesional curettage without local recurrence in the follow-up. CONCLUSIONS: Sequential instillations of polidocanol are a promising, minimally invasive treatment method for ABCs of the pelvis and can be well combined with transarterial embolization. aneurysmal bone cyst polidocanol injection polidocanol instillation Figures Figure 1 Figure 2 Introduction The aneurysmal bone cyst (ABC) is a benign but rapidly and aggressively growing tumor that occurs in adolescents and young adults. It was first described by Jaffe and Lichtenstein in 1942.[ 1 ] 80% of the patients with ABCs are younger than twenty years.[ 2 ] ABCs can appear in the whole skeleton but usually affect the metaphysis of long bones or the pelvis [ 3 ]. 70% of the cysts appear as primary lesions, 30% are secondary with preexisting osseous lesions.[ 4 ] Patients usually present with pain and swelling in the affected region and sometimes pathological fractures can occur. If the cyst expands progressively, it forms an expansile mass and may be visible or palpable. In plain radiographs an osteolytic, multilobulated lesion can be detected; the magnetic resonance imaging shows cystic formations with typical fluid-fluid levels due to blood sedimentation.[ 5 ] Two major classifications are used for distinguishing cystic lesions of the bone: the Enneking [ 6 ] (stage 1: latent cyst; stage 2: active cyst; stage 3 aggressive cysts) and the Capanna [ 7 ] classification (type 1: central location without expansile growth; type 2 whole bony segment is affected, expansile growth; type 3: only one metaphyseal cortex is affected; type 5: periosteal lesion with peripheral expansion and cortical erosion). ABCs have to be diagnosed by biopsy and histopathological examinations.[ 8 ] The pathophysiology of ABCs is debatable.[ 4 ] Former studies claimed that an increased vascular pressure in the venous network of the cyst leads to destruction of the bone matrix.[ 5 , 9 , 10 ] Recent cytogenetic and molecular studies underline the neoplastic character of ABCs due to of specific translocations of the ubiquitin-specific protease (USP) 6 gene.[ 11 ] USP6 gene arrangements are seen in 70% of primary ABCs and are lacking in secondary ABCs[ 12 ]. Histologically ABCs contain blood filled spaces surrounded by variable thick fibrous septae. Within the septae are uniform blad spindle cells, multinucleated giant cells, capillaries and varying amount of matrix findable.[ 4 ] In immunohistochemical studies CD68 and P63 were specific for ABCs, whereas only CD68 showed prognostic value for local recurrence.[ 13 ] By fluorescent in situ hybridization and next generation sequencing USP6 gene arrangements can be detected in up to 100% of the cases.[ 14 ] With these examinations primary ABCs can be differentiated from secondary ABCs and other bone affecting tumors. Other bone pathologies like a chondroblastoma, a giant cell tumor of bone, a chondromyxoid fibroma, a fibrous dysplasia or a telangiectatic osteosarcoma have to be excluded. In rare cases a malignant transformations of ABCs is reported.[ 4 ] Different treatment modalities are described in the literature and can be divided into nonoperative, minimally invasive and operative treatment options. Among those are wide resection, marginal resection, intralesional resection such as curettage with or without adjuvants, selective arterial embolization, intralesional sclerotherapy using polidocanol or the systemic application of denosumab.[ 5 ] The optimal treatment, especially in the pelvis is still under discussion. A wide surgical resection results in best local control rate but can evoke other complications depending on the dimension of the resection and the localization.[ 15 ] Especially in the pelvis a wide resection may cause severe restrictions on the functional outcome. The most common therapy for ABCs is an intralesional curettage with the use of adjuvants. Adjuvants can be the use of a high-speed drill, phenol, hydrogen peroxide or cement augmentation with polymethylacrylat (PMMA). Novais et al. described intralesional curettage extended with a high-speed burr and bone grafting in a study with 13 patients with an ABC of the pelvis as sufficient way of therapy.[ 16 ] Even local MRI-guided percutaneous cryoablation has been used as adjuvant therapy.[ 17 ] Local recurrence rates after intralesional curettage of up to 50% are reported in the literature.[ 18 ] Transarterial embolization of ABCs can be used as adjuvant or single therapy when surgical resection is difficult or connected with high risk of complications. Henrichs et al. reported the successful use of transarterial embolization in ABCs of the sacrum as single therapy. [ 19 ] Sclerosants such as polidocanol can be used for instillation of the cyst and lead stepwise to a resolution of the cystic lesion and progressive sclerosis. Rastogi et al. reported a cure rate of 97% in a study with 72 patients with primary ABC.[ 20 ] The RANKL inhibitor denosumab can be used in cases when surgical procedures and/or embolization are insufficient or without effect. Purpose of the study : Several case reports and only one larger historic case series about the manifestation of ABCs in the pelvis and sacrum are findable in the literature.[ 21 – 23 ] The present study describes 17 cases of an ABC of the pelvis treated by intralesional curettage, percutaneous instillation of polidocanol and, in selected cases, arterial embolization. Patients And Methods The study protocol of this study was approved by the regional ethics committee (reference no.: 2019-592-f-S). This single-center study is a retrospective review of 74 patients with a primary ABC, who were treated at a tertiary academic referral center for orthopedic oncology from 2009–2020. Among those, 17 ABCs were located in the pelvis or sacrum. No financial support was received for this study. Epidemiological data, radiographic and histological examinations, different surgical techniques, complications and especially local recurrence were analysed. Imaging studies at time of presentation, including plain radiographs and MR-scans were reviewed in each case. The ABCs were classified radiologically by two systems: the Enneking classification and the classification according to Rastogi et al..[ 6 , 7 , 24 ] The classification according to Rastogi et al. was exclusively used for the instillation group.[ 24 ] The diagnosis was made by histological and immunohistological examinations by expert pathologists. In addition to the standard histopathological examination, fluorescence in situ hybridization (FISH) and next generation sequencing were used to differentiate primary from secondary ABCs. The following treatment options were performed: intralesional curettage with hydrogen peroxide as adjuvant and sequential instillation of polidocanol (Aethoxysklerol, 3%, Kreussler pharma; Wiesbaden, Germany). Until 2014 intralesional curettage was the standard treatment for primary ABCs in our institution. For defect reconstruction after intralesional curettage a synthetic calcium phosphate bone graft (Actifuse ® ; Baxter Deutschland; Unterschleißheim, Germany) or PMMA (Palacos ® ; Heraeus Medical; Wehrheim, Germany) were used. Since 2014 sequential instillations of polidocanol (Aethoxysklerol® 3%; Kreussler pharma; Wiesbaden, Germany) became the standard treatment for primary ABCs. Short- or long-term complications were reviewed. Patients underwent follow-up with clinical and radiographic examinations (radiographs and MR-scans) at three-month intervals in the first two years and at six-month intervals for the following four years. Due to the low number of patients in the different treatment groups the statistical analysis was predominantly performed descriptively. Statistical analysis was performed with the use of SPSS Statistics (IBM Corp. Released 2019, Version 26.0. Armonk, NY, USA). Continuous variables like age and time of follow up were described using the mean and the maximum and minimum. Cyst volumes before and after treatment were analysed using the Wilcoxon test. Results This study includes 17 patients with the histopathological diagnosis of a primary ABC of the pelvis. Out of these, six patients were male (35.3%) and eleven patients female (64.7%; Table 1 ); the mean age was 17.59 (9–49) years. The mean follow-up time was 50.18 months (12–136 months). The most common location (Table 1 ) was the pubis (6; 35.3%), followed by the ilium (6; 35.3%), the sacrum (3; 17.6%) and the ischium (2; 11.8%). According to the Enneking [ 6 ] classification six lesions were rated as active and 11 as aggressive. The examined ABCs had a mean initial volume of 54.26 cm 3 (7.97–222.56 cm 3 ) in MRI scans. In eight cases an intralesional curettage (Fig. 1a-e) was performed. According to the Enneking classification four lesions of this subgroup were rated as active and four lesions as aggressive. The mean cyst volume in the curettage group was 50.97 cm 3 (7.97-222.56 cm 3 ). In one case an additional transarterial embolization was performed before curettage. In 50% (4/8 cases) a histologically confirmed local recurrence occurred after intralesional curettage. In one case of local recurrence a re-curettage was performed, in 3 cases a series of sequential instillations of polidocanol was started. The mean time until local recurrence arose was 62.6 (29–65) months. In two cases a wound healing disorder was observed in the curettage group. After treatment of recurrence, no second recurrence was observed in the study group. In 7 cases a series of sequential polidocanol instillations (Fig. 2a-e) was performed as primary treatment. According to the Enneking classification one lesion of this subgroup was rated as active and six lesions as aggressive. The mean cyst volume in the instillation group was 58.96 cm³ (20.18-113.26 cm³). The mean number of instillations was 6.7 (3–10); the mean volume of polidocanol was 6 ml (2–10 ml). Transarterial embolization was performed in four cases. The mean cyst volume after instillation therapy was reduced significantly (p = 0.018) to 21.2 cm³ (0-59.98 cm³) in the sense of a persistent disease without need of additional treatment. In one case (14.3%) persistent cystic formations including typical fluid-fluid levels without progressive sclerosis of the cyst’s wall were observed. This case was classified as persistent disease with need of additional treatment and an intralesional curettage was performed. No local recurrence was observed after additional curettage. Mean duration until end of treatment in the instillation subgroup was 9.1 (1–23) months. In one case of an ABC in the study group a marginal resection was performed; in this case no local recurrence was detected. One further case did not receive any kind of surgical treatment but simple observation due to an asymptomatic course of disease. Discussion The ABC is a rare, benign, but locally aggressive bone tumor with a high rate of local recurrence. Diagnosing an ABC is often challenging, the biopsy is compulsory, and the results of the radiologic and histopathological examinations have to be seen in synopsis with the clinic history. A differentiation between primary and secondary ABCs is important and highly relevant for an adequate treatment. This study describes the results of three common treatment options of ABCs at the pelvis: Intralesional curettage, sequential percutaneous instillation of polidocanol and marginal resection. Sex distribution (p = 0.414), age (p = 0.813) and pre-interventional MRI volume (p = 0.298) did not differ significantly in the curettage- and instillation subgroup. Only one patient was treated by a marginal resection; instillation and curettage were each used in equally limited numbers of cases. Our study showed a local recurrence in 4/8 cases (50%) treated by intralesional curettage. Regarding ABCs of the pelvis Panayiotis et al.[ 23 ] described a local recurrence in 14% of the cases in a historic study cohort of 35 patients treated by excision-curettage or intralesional excision between 1921 and 1996. Novais et al.[ 16 ] reported an equally low recurrence rate of 8% in a study collective of 13 patients who were treated by intralesional curettage. Among these patients five were treated by transarterial embolization preoperatively. Larger studies on patients with primary ABCs in various locations described local recurrence rates of more than 40% after the use of intralesional curettage.[ 4 , 5 , 18 ] Especially in the pelvis, where intralesional curettage is more challenging due to the difficult surgical approach, low local recurrence rates of less than 15% are hardly achievable. In the instillation subgroup 6/7 (86%) patients were treated successfully by instillation therapy. 1/7 cases (14%) with a persistent disease needed further treatment in terms of an intralesional curettage. After a combination of polidocanol instillations and additional intralesional curettage no recurrence was observed. Rastogi et al.[ 20 ] demonstrated the good response of primary ABCs to polidocanol instillation in a series of 72 patients with primary ABCs: A reduction of the initial cyst volume to 25% or less was achieved in 66.7% of the cases. Overall, 30.5% of Rastogi et al.’s collective showed a residual volume of 25–50% after treatment. In our study the mean initial cyst volume decreased significantly from 59 to 22.1 cm³ (p = 0.018) after polidocanol instillation. In three cases (3/7;42.9%) a cyst volume reduction to 25% or less of the initial volume was achieved. Rastogi et al. classified “inadequate healing” as a residual cyst volume of more than 50% of the initial volume and reported this in 2.8% of the cases only.[ 20 ] The present study showed a residual volume of 50% or more in 57% (4/7) of the patients. The significant difference concerning adequate and inadequate healing in both studies may be explainable by (1.) the lower initial cyst volume of Rastogi’s collective (26.1 cm³) and (2.) the low number of ABCs in the pelvis (n = 3). Several other studies described a single instillation of polidocanol as sufficient in treatment of ABCs.[ 20 , 25 , 26 ] In our study the mean number of instillations was 6.7 and not a single patient was treated by a single instillation sufficiently. Rastogi et al. described a mean number of three instillations but even about a successful healing process after a single instillation in rare cases. [ 20 ] Masthoff et al. [ 27 ] showed the successful treatment of 16 patients with refractory and nonresectable ABCs by transarterial embolization in addition to percutaneous sclerotherapy. In 9/16 cases the ABCs were located in the pelvis. A mean of 1.6 transarterial embolizations and 3.2 percutaneous sclerotherapies were performed. No recurrence was seen in a median follow-up time of 27.3 months. The present study gives consent to other authors concluding that the percutaneous instillation of polidocanol is a less invasive procedure than intralesional curettage.[ 28 ] Varshney et al. [ 28 ] reported about a comparative study of 94 patients with a primary ABC who were treated by intralesional curettage or sequential percutaneous instillation of polidocanol. No significant differences for recurrence rates between the two treatment groups were found by the authors. They conclude that the less invasive character of the instillation therapy justifies it as primary attempt of treatment. In conclusion, our results along with the aforementioned studies show that the percutaneous instillation of polidocanol is a less invasive procedure than intralesional curettage and is mostly favorable for cystic lesions in the pelvis due to its minimally invasive character. Moreover, we see advantages of the instillation therapy as a treatment of ABCs with a high initial cyst volume and for cystic lesions in locations with a difficult surgical approach. Percutaneous instillation can be well combined with transarterial embolization and can be performed in general or local anesthesia in an outpatient clinic without hospitalization. In the present study no patient received denosumab, however, denosumab can be used in cases when surgical procedures and/or embolization are not successful or applicable. Lange et al. used denosumab in two cases of ABC of the spine where embolization failed [ 29 ]. This single-institution series has severe limitations due to its retrospective, observative character and the very low number of patients. The patients and compared groups were not randomized and predominantly descriptive statistical analysis was conducted. Despite the limitations the present case series presents useful descriptive information for the diagnosis and treatment of ABCs of the pelvis. Conclusion Sequential percutaneous instillations of polidocanol combined with transarterial embolization are a relevant treatment option for ABCs of the pelvis. The less invasive character of the instillation justifies it as preferable therapy, especially for borderline resectable lesions. Nonetheless, several instillations can be necessary. In some cases a conversion to intralesional curettage may be inevitable. Abbreviations ABC Aneurysmal bone cyst Declarations Funding : No financial support was received for this study. Availability of data and materials: The datasets used and/or analysed during the study are available from the corresponding author on reasonable request. Code availability: Not applicable. Ethics declarations: The study protocol was approved by the regional ethics committee (reference no.: 2019-592-f-S). Consent to participate: Not applicable. Consent to publish: A written informed consent was obtained from all patients and their families for publication of this study and any accompanying images. Conflict of interest: The authors hereby declare that there were no conflicts of interest in this review. Author information: Contributions: Niklas Deventer: data acquisition, analysis, writing of the article, Tymoteusz Budny: writing of the article, critical review of the article or its intellectual content, Georg Gosheger: critical review of the article or its intellectual content, Marieke de Vaal: critical review of the article or its intellectual content, Jana Burkhardt: analysis, critical review of the article, Nils Deventer: data acquisition, analysis, critical review of the article Corresponding author: Niklas Deventer Type of study: Level IV study, retrospective case series References Jaffe HL LL: Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis . 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Tables Table 1: overview of the study collective gender age localization volume in cm 3 Enneking classification Rastogi classification treatment residual volume in cm 3 additional treatment recurrence/ persistent disease necessity of treatment complications number of instilations second recurrence follow-up (months) 1 female 49 sacrum 8 aggressive not applicable intralesional curettage + PMMA - No recurrence no none - no 11 2 male 13 ischiium 12 active not applicable intralesional curettage + PMMA - no recurrence no none - no 28 3 female 15 pubis 38,1 aggressive not applicable intralesional curettage + bone substitute - no no no none - no 36 4 female 18 ilium 11,9 active not applicable intralesional curettage + bone substitute - no no no none - no 7 5 female 15 ilium 42 active not applicable biopsy + watch and wait - no no no none - no 12 6 male 11 ischium 45,7 aggressive not applicable marginal resection and reconstruction with PMMA - no persistent disease no healing disorder - no 23 7 female 12 sacrum 35 aggressive not applicable marginal resection - embolization persistent disease no none - no 44 8 female 9 ilium 27,7 active not applicable intralesional curettage + bone substitute - no recurrence yes none yes 100 9 male 42 pubis 66,9 aggressive not applicable intralesional curettage + PMMA - embolization recurrence yes none - no 136 10 male 11 ilium 222,6 active not applicable intralesional curettage + PMMA - embolization persistent disease yes healing disorder - no 89 11 female 14 ilium 43,8 active I instillation of polidocanol 0 no no no none 3 no 59 12 female 16 pubis 106 aggressive I Instillation of polidocanol 9,1 no persistent disease no none 7 no 37 13 male 16 pubis 40,1 aggressive I Instillation of polidocanol 1,94 embolization persistent disease yes none 7 no 50 14 male 16 pubis 20,2 aggressive III Instillation of polidocanol 14,69 no persistent disease no none 8 no 51 15 female 16 pubis 56,7 aggressive III Instillation of polidocanol 31,27 embolization persistent disease no none 6 no 58 16 female 10 ilium 113,3 aggressive III Instillation of polidocanol 58,98 embolization persistent disease no none 10 no 62 17 female 16 sacrum 32,7 aggressiv IV Instillation of polydocanol 32,44 embolization persistent disease no none 6 no 50 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Major revision 22 Mar, 2022 Reviews received at journal 15 Mar, 2022 Reviewers agreed at journal 15 Mar, 2022 Reviewers invited by journal 15 Mar, 2022 Editor assigned by journal 15 Mar, 2022 Editor invited by journal 15 Mar, 2022 Submission checks completed at journal 15 Mar, 2022 First submitted to journal 27 Feb, 2022 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1401862","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":90840466,"identity":"1c6619e5-8f06-49c0-970e-4a4c296f874e","order_by":0,"name":"Niklas Deventer","email":"data:image/png;base64,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","orcid":"","institution":"Department of Orthopedics and Tumororthopedics, University Hospital Muenster","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Niklas","middleName":"","lastName":"Deventer","suffix":""},{"id":90840467,"identity":"65b45947-a049-41db-a699-99dfd1d3b40b","order_by":1,"name":"Tymoteusz Budny","email":"","orcid":"","institution":"Department of Orthopedics and Tumororthopedics, University Hospital Muenster","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Tymoteusz","middleName":"","lastName":"Budny","suffix":""},{"id":90840468,"identity":"9031ea8a-e360-4ec9-bb38-07a2d590c300","order_by":2,"name":"Georg Gosheger","email":"","orcid":"","institution":"Department of Orthopedics and Tumororthopedics, University Hospital Muenster","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Georg","middleName":"","lastName":"Gosheger","suffix":""},{"id":90840469,"identity":"4e7eb974-b820-44c8-acd5-d47b166f96de","order_by":3,"name":"Marieke Vaal","email":"","orcid":"","institution":"Department of Orthopedics and Tumororthopedics, University Hospital Muenster","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Marieke","middleName":"","lastName":"Vaal","suffix":""},{"id":90840471,"identity":"3e680cc6-fa79-47cc-9887-7d8390f2aee6","order_by":4,"name":"Jana Burkhardt","email":"","orcid":"","institution":"University Children's Hospital Muenster","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jana","middleName":"","lastName":"Burkhardt","suffix":""},{"id":90840473,"identity":"af08621d-6266-4dac-8813-2a57ed01cfbf","order_by":5,"name":"Nils Deventer","email":"","orcid":"","institution":"University Children's Hospital Muenster","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Nils","middleName":"","lastName":"Deventer","suffix":""}],"badges":[],"createdAt":"2022-02-27 22:59:04","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1401862/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1401862/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":19305007,"identity":"9e83de48-0744-4015-aea2-9accd96fb421","added_by":"auto","created_at":"2022-03-16 18:48:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":4388104,"visible":true,"origin":"","legend":"\u003cp\u003ea-e: manifestation of an ABC in the left ilium and ischium: simple radiograph (1a) and MRI scan (1b); preoperative angiography without embolization (1c); radiograph after intralesional curettage and cement augmentation (1d), MRI scan 24 months after operation with small residual cystic element (1e)\u003c/p\u003e","description":"","filename":"fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-1401862/v1/485c2f18d84f568e76e3016b.png"},{"id":19305215,"identity":"aad4802a-157a-42c4-91e9-aa19cd2b9e59","added_by":"auto","created_at":"2022-03-16 18:51:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":6194575,"visible":true,"origin":"","legend":"\u003cp\u003ea-e: ABC of the right ilium of a 15-year-old patient: simple radiograph (2a); MRI scan (2b); transarterial embolization and percutaneous sclerotherapy (2c), simple radiographs six weeks (left) and 24 months after the sixth and last instillation (right; 2d); MRI scan 24 months after the last sclerotherapy with constant residual cystic elements (2e)\u003c/p\u003e","description":"","filename":"fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-1401862/v1/133d2fa9cda1c21096f67761.png"},{"id":19305233,"identity":"8355a0cc-1731-41f6-885f-46e3b699cda1","added_by":"auto","created_at":"2022-03-16 18:51:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":756083,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1401862/v1/ddb77f6b-8735-464a-afcb-a82b55ff74b1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Aneurysmal Bone Cyst of the Pelvis: a single-center study of 17 cases","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe aneurysmal bone cyst (ABC) is a benign but rapidly and aggressively growing tumor that occurs in adolescents and young adults. It was first described by Jaffe and Lichtenstein in 1942.[\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e] 80% of the patients with ABCs are younger than twenty years.[\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e] ABCs can appear in the whole skeleton but usually affect the metaphysis of long bones or the pelvis [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e]. 70% of the cysts appear as primary lesions, 30% are secondary with preexisting osseous lesions.[\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e\n\u003cp\u003ePatients usually present with pain and swelling in the affected region and sometimes pathological fractures can occur. If the cyst expands progressively, it forms an expansile mass and may be visible or palpable. In plain radiographs an osteolytic, multilobulated lesion can be detected; the magnetic resonance imaging shows cystic formations with typical fluid-fluid levels due to blood sedimentation.[\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e] Two major classifications are used for distinguishing cystic lesions of the bone: the Enneking [\u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e] (stage 1: latent cyst; stage 2: active cyst; stage 3 aggressive cysts) and the Capanna [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e] classification (type 1: central location without expansile growth; type 2 whole bony segment is affected, expansile growth; type 3: only one metaphyseal cortex is affected; type 5: periosteal lesion with peripheral expansion and cortical erosion). ABCs have to be diagnosed by biopsy and histopathological examinations.[\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/p\u003e\n\u003cp\u003eThe pathophysiology of ABCs is debatable.[\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e] Former studies claimed that an increased vascular pressure in the venous network of the cyst leads to destruction of the bone matrix.[\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e] Recent cytogenetic and molecular studies underline the neoplastic character of ABCs due to of specific translocations of the ubiquitin-specific protease (USP) 6 gene.[\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e] USP6 gene arrangements are seen in 70% of primary ABCs and are lacking in secondary ABCs[\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e]. Histologically ABCs contain blood filled spaces surrounded by variable thick fibrous septae. Within the septae are uniform blad spindle cells, multinucleated giant cells, capillaries and varying amount of matrix findable.[\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e] In immunohistochemical studies CD68 and P63 were specific for ABCs, whereas only CD68 showed prognostic value for local recurrence.[\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e] By fluorescent in situ hybridization and next generation sequencing USP6 gene arrangements can be detected in up to 100% of the cases.[\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e] With these examinations primary ABCs can be differentiated from secondary ABCs and other bone affecting tumors. Other bone pathologies like a chondroblastoma, a giant cell tumor of bone, a chondromyxoid fibroma, a fibrous dysplasia or a telangiectatic osteosarcoma have to be excluded. In rare cases a malignant transformations of ABCs is reported.[\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e\n\u003cp\u003eDifferent treatment modalities are described in the literature and can be divided into nonoperative, minimally invasive and operative treatment options. Among those are wide resection, marginal resection, intralesional resection such as curettage with or without adjuvants, selective arterial embolization, intralesional sclerotherapy using polidocanol or the systemic application of denosumab.[\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e] The optimal treatment, especially in the pelvis is still under discussion. A wide surgical resection results in best local control rate but can evoke other complications depending on the dimension of the resection and the localization.[\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e] Especially in the pelvis a wide resection may cause severe restrictions on the functional outcome. The most common therapy for ABCs is an intralesional curettage with the use of adjuvants. Adjuvants can be the use of a high-speed drill, phenol, hydrogen peroxide or cement augmentation with polymethylacrylat (PMMA). Novais et al. described intralesional curettage extended with a high-speed burr and bone grafting in a study with 13 patients with an ABC of the pelvis as sufficient way of therapy.[\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e] Even local MRI-guided percutaneous cryoablation has been used as adjuvant therapy.[\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e] Local recurrence rates after intralesional curettage of up to 50% are reported in the literature.[\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e] Transarterial embolization of ABCs can be used as adjuvant or single therapy when surgical resection is difficult or connected with high risk of complications. Henrichs et al. reported the successful use of transarterial embolization in ABCs of the sacrum as single therapy. [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e] Sclerosants such as polidocanol can be used for instillation of the cyst and lead stepwise to a resolution of the cystic lesion and progressive sclerosis. Rastogi et al. reported a cure rate of 97% in a study with 72 patients with primary ABC.[\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e] The RANKL inhibitor denosumab can be used in cases when surgical procedures and/or embolization are insufficient or without effect.\u003c/p\u003e\n\u003cp\u003e\u003cspan class=\"ItalicUnderline\" name=\"Emphasis\" type=\"ItalicUnderline\"\u003ePurpose of the study\u003c/span\u003e: Several case reports and only one larger historic case series about the manifestation of ABCs in the pelvis and sacrum are findable in the literature.[\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e] The present study describes 17 cases of an ABC of the pelvis treated by intralesional curettage, percutaneous instillation of polidocanol and, in selected cases, arterial embolization.\u003c/p\u003e"},{"header":"Patients And Methods","content":"\u003cp\u003eThe study protocol of this study was approved by the regional ethics committee (reference no.: 2019-592-f-S).\u003c/p\u003e \u003cp\u003e This single-center study is a retrospective review of 74 patients with a primary ABC, who were treated at a tertiary academic referral center for orthopedic oncology from 2009\u0026ndash;2020. Among those, 17 ABCs were located in the pelvis or sacrum. No financial support was received for this study.\u003c/p\u003e \u003cp\u003eEpidemiological data, radiographic and histological examinations, different surgical techniques, complications and especially local recurrence were analysed. Imaging studies at time of presentation, including plain radiographs and MR-scans were reviewed in each case. The ABCs were classified radiologically by two systems: the Enneking classification and the classification according to Rastogi et al..[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] The classification according to Rastogi et al. was exclusively used for the instillation group.[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] The diagnosis was made by histological and immunohistological examinations by expert pathologists. In addition to the standard histopathological examination, fluorescence in situ hybridization (FISH) and next generation sequencing were used to differentiate primary from secondary ABCs.\u003c/p\u003e \u003cp\u003eThe following treatment options were performed: intralesional curettage with hydrogen peroxide as adjuvant and sequential instillation of polidocanol (Aethoxysklerol, 3%, Kreussler pharma; Wiesbaden, Germany). Until 2014 intralesional curettage was the standard treatment for primary ABCs in our institution. For defect reconstruction after intralesional curettage a synthetic calcium phosphate bone graft (Actifuse\u003csup\u003e\u0026reg;\u003c/sup\u003e; Baxter Deutschland; Unterschlei\u0026szlig;heim, Germany) or PMMA (Palacos\u003csup\u003e\u0026reg;\u003c/sup\u003e; Heraeus Medical; Wehrheim, Germany) were used. Since 2014 sequential instillations of polidocanol (Aethoxysklerol\u0026reg; 3%; Kreussler pharma; Wiesbaden, Germany) became the standard treatment for primary ABCs. Short- or long-term complications were reviewed. Patients underwent follow-up with clinical and radiographic examinations (radiographs and MR-scans) at three-month intervals in the first two years and at six-month intervals for the following four years.\u003c/p\u003e \u003cp\u003eDue to the low number of patients in the different treatment groups the statistical analysis was predominantly performed descriptively. Statistical analysis was performed with the use of SPSS Statistics (IBM Corp. Released 2019, Version 26.0. Armonk, NY, USA). Continuous variables like age and time of follow up were described using the mean and the maximum and minimum. Cyst volumes before and after treatment were analysed using the Wilcoxon test.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThis study includes 17 patients with the histopathological diagnosis of a primary ABC of the pelvis. Out of these, six patients were male (35.3%) and eleven patients female (64.7%; Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); the mean age was 17.59 (9\u0026ndash;49) years. The mean follow-up time was 50.18 months (12\u0026ndash;136 months). The most common location (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) was the pubis (6; 35.3%), followed by the ilium (6; 35.3%), the sacrum (3; 17.6%) and the ischium (2; 11.8%). According to the Enneking [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] classification six lesions were rated as active and 11 as aggressive. The examined ABCs had a mean initial volume of 54.26 cm\u003csup\u003e3\u003c/sup\u003e (7.97\u0026ndash;222.56 cm\u003csup\u003e3\u003c/sup\u003e) in MRI scans.\u003c/p\u003e \u003cp\u003eIn eight cases an intralesional curettage (Fig.\u0026nbsp;1a-e) was performed. According to the Enneking classification four lesions of this subgroup were rated as active and four lesions as aggressive. The mean cyst volume in the curettage group was 50.97 cm\u003csup\u003e3\u003c/sup\u003e (7.97-222.56 cm\u003csup\u003e3\u003c/sup\u003e). In one case an additional transarterial embolization was performed before curettage. In 50% (4/8 cases) a histologically confirmed local recurrence occurred after intralesional curettage. In one case of local recurrence a re-curettage was performed, in 3 cases a series of sequential instillations of polidocanol was started. The mean time until local recurrence arose was 62.6 (29\u0026ndash;65) months. In two cases a wound healing disorder was observed in the curettage group. After treatment of recurrence, no second recurrence was observed in the study group.\u003c/p\u003e \u003cp\u003eIn 7 cases a series of sequential polidocanol instillations (Fig.\u0026nbsp;2a-e) was performed as primary treatment. According to the Enneking classification one lesion of this subgroup was rated as active and six lesions as aggressive. The mean cyst volume in the instillation group was 58.96 cm\u0026sup3; (20.18-113.26 cm\u0026sup3;). The mean number of instillations was 6.7 (3\u0026ndash;10); the mean volume of polidocanol was 6 ml (2\u0026ndash;10 ml). Transarterial embolization was performed in four cases. The mean cyst volume after instillation therapy was reduced significantly (p\u0026thinsp;=\u0026thinsp;0.018) to 21.2 cm\u0026sup3; (0-59.98 cm\u0026sup3;) in the sense of a persistent disease without need of additional treatment. In one case (14.3%) persistent cystic formations including typical fluid-fluid levels without progressive sclerosis of the cyst\u0026rsquo;s wall were observed. This case was classified as persistent disease with need of additional treatment and an intralesional curettage was performed. No local recurrence was observed after additional curettage. Mean duration until end of treatment in the instillation subgroup was 9.1 (1\u0026ndash;23) months.\u003c/p\u003e \u003cp\u003eIn one case of an ABC in the study group a marginal resection was performed; in this case no local recurrence was detected. One further case did not receive any kind of surgical treatment but simple observation due to an asymptomatic course of disease.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe ABC is a rare, benign, but locally aggressive bone tumor with a high rate of local recurrence. Diagnosing an ABC is often challenging, the biopsy is compulsory, and the results of the radiologic and histopathological examinations have to be seen in synopsis with the clinic history. A differentiation between primary and secondary ABCs is important and highly relevant for an adequate treatment.\u003c/p\u003e \u003cp\u003eThis study describes the results of three common treatment options of ABCs at the pelvis: Intralesional curettage, sequential percutaneous instillation of polidocanol and marginal resection. Sex distribution (p\u0026thinsp;=\u0026thinsp;0.414), age (p\u0026thinsp;=\u0026thinsp;0.813) and pre-interventional MRI volume (p\u0026thinsp;=\u0026thinsp;0.298) did not differ significantly in the curettage- and instillation subgroup. Only one patient was treated by a marginal resection; instillation and curettage were each used in equally limited numbers of cases. Our study showed a local recurrence in 4/8 cases (50%) treated by intralesional curettage. Regarding ABCs of the pelvis Panayiotis et al.[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] described a local recurrence in 14% of the cases in a historic study cohort of 35 patients treated by excision-curettage or intralesional excision between 1921 and 1996. Novais et al.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] reported an equally low recurrence rate of 8% in a study collective of 13 patients who were treated by intralesional curettage. Among these patients five were treated by transarterial embolization preoperatively. Larger studies on patients with primary ABCs in various locations described local recurrence rates of more than 40% after the use of intralesional curettage.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] Especially in the pelvis, where intralesional curettage is more challenging due to the difficult surgical approach, low local recurrence rates of less than 15% are hardly achievable.\u003c/p\u003e \u003cp\u003eIn the instillation subgroup 6/7 (86%) patients were treated successfully by instillation therapy. 1/7 cases (14%) with a persistent disease needed further treatment in terms of an intralesional curettage. After a combination of polidocanol instillations and additional intralesional curettage no recurrence was observed. Rastogi et al.[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] demonstrated the good response of primary ABCs to polidocanol instillation in a series of 72 patients with primary ABCs: A reduction of the initial cyst volume to 25% or less was achieved in 66.7% of the cases. Overall, 30.5% of Rastogi et al.\u0026rsquo;s collective showed a residual volume of 25\u0026ndash;50% after treatment. In our study the mean initial cyst volume decreased significantly from 59 to 22.1 cm\u0026sup3; (p\u0026thinsp;=\u0026thinsp;0.018) after polidocanol instillation. In three cases (3/7;42.9%) a cyst volume reduction to 25% or less of the initial volume was achieved. Rastogi et al. classified \u0026ldquo;inadequate healing\u0026rdquo; as a residual cyst volume of more than 50% of the initial volume and reported this in 2.8% of the cases only.[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] The present study showed a residual volume of 50% or more in 57% (4/7) of the patients. The significant difference concerning adequate and inadequate healing in both studies may be explainable by (1.) the lower initial cyst volume of Rastogi\u0026rsquo;s collective (26.1 cm\u0026sup3;) and (2.) the low number of ABCs in the pelvis (n\u0026thinsp;=\u0026thinsp;3). Several other studies described a single instillation of polidocanol as sufficient in treatment of ABCs.[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] In our study the mean number of instillations was 6.7 and not a single patient was treated by a single instillation sufficiently. Rastogi et al. described a mean number of three instillations but even about a successful healing process after a single instillation in rare cases. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] Masthoff et al. [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] showed the successful treatment of 16 patients with refractory and nonresectable ABCs by transarterial embolization in addition to percutaneous sclerotherapy. In 9/16 cases the ABCs were located in the pelvis. A mean of 1.6 transarterial embolizations and 3.2 percutaneous sclerotherapies were performed. No recurrence was seen in a median follow-up time of 27.3 months. The present study gives consent to other authors concluding that the percutaneous instillation of polidocanol is a less invasive procedure than intralesional curettage.[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] Varshney et al. [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] reported about a comparative study of 94 patients with a primary ABC who were treated by intralesional curettage or sequential percutaneous instillation of polidocanol. No significant differences for recurrence rates between the two treatment groups were found by the authors. They conclude that the less invasive character of the instillation therapy justifies it as primary attempt of treatment. In conclusion, our results along with the aforementioned studies show that the percutaneous instillation of polidocanol is a less invasive procedure than intralesional curettage and is mostly favorable for cystic lesions in the pelvis due to its minimally invasive character. Moreover, we see advantages of the instillation therapy as a treatment of ABCs with a high initial cyst volume and for cystic lesions in locations with a difficult surgical approach. Percutaneous instillation can be well combined with transarterial embolization and can be performed in general or local anesthesia in an outpatient clinic without hospitalization.\u003c/p\u003e \u003cp\u003eIn the present study no patient received denosumab, however, denosumab can be used in cases when surgical procedures and/or embolization are not successful or applicable. Lange et al. used denosumab in two cases of ABC of the spine where embolization failed [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis single-institution series has severe limitations due to its retrospective, observative character and the very low number of patients. The patients and compared groups were not randomized and predominantly descriptive statistical analysis was conducted. Despite the limitations the present case series presents useful descriptive information for the diagnosis and treatment of ABCs of the pelvis.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eSequential percutaneous instillations of polidocanol combined with transarterial embolization are a relevant treatment option for ABCs of the pelvis. The less invasive character of the instillation justifies it as preferable therapy, especially for borderline resectable lesions. Nonetheless, several instillations can be necessary. In some cases a conversion to intralesional curettage may be inevitable.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"13.731825525040387%\"\u003e\n \u003cp\u003eABC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"86.26817447495961%\"\u003e\n \u003cp\u003eAneurysmal bone cyst\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cu\u003e\u003cstrong\u003eFunding\u003c/strong\u003e:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eNo financial support was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eAvailability of data and materials:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eCode availability:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eEthics declarations:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the regional ethics committee (reference no.: 2019-592-f-S).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eConsent to participate:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eConsent to publish:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA written informed consent was obtained from all patients and their families for publication of this study and any accompanying images. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eConflict of interest:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors hereby declare that there were no conflicts of interest in this review.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eAuthor information:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eContributions:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNiklas Deventer: data acquisition, analysis, writing of the article, Tymoteusz Budny: writing of the article, critical review of the article or its intellectual content, Georg Gosheger: critical review of the article or its intellectual content, Marieke de Vaal: critical review of the article or its intellectual content, Jana Burkhardt: analysis, critical review of the article, Nils Deventer: data acquisition, analysis, critical review of the article \u003c/p\u003e\n\u003cp\u003eCorresponding author: Niklas Deventer \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eType of study: \u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLevel IV study, retrospective case series\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eJaffe HL LL: \u003cb\u003eSolitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis\u003c/b\u003e. 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Arch Orthop Trauma Surg 1990, \u003cb\u003e109\u003c/b\u003e(4):221\u0026ndash;223.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNovais EN, Zimmerman AK, Lewallen LW, Rose PS, Sim FH, McIntosh AL: \u003cb\u003eFunctional outcomes and quality of life following surgical treatment of aneurysmal bone cysts of the pelvis in children\u003c/b\u003e. J Child Orthop 2014, \u003cb\u003e8\u003c/b\u003e(3):281\u0026ndash;288.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFritz J, Sonnow L, Morris CD: \u003cb\u003eAdjuvant MRI-guided percutaneous cryoablation treatment for aneurysmal bone cyst\u003c/b\u003e. Skeletal Radiol 2019, \u003cb\u003e48\u003c/b\u003e(7):1149\u0026ndash;1153.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrahneis F, Klein A, Baur-Melnyk A, Knosel T, Birkenmaier C, Jansson V, Durr HR: \u003cb\u003eAneurysmal bone cyst: A review of 65 patients\u003c/b\u003e. J Bone Oncol 2019, \u003cb\u003e18\u003c/b\u003e:100255.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHenrichs MP, Beck L, Gosheger G, Streitbuerger A, Koehler M, Heindel W, Hardes J, Vieth V: \u003cb\u003eSelective arterial Embolisation of Aneurysmal Bone Cysts of the Sacrum: a promising Alternative to Surgery\u003c/b\u003e. Rofo 2016, \u003cb\u003e188\u003c/b\u003e(1):53\u0026ndash;59.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRastogi S, Varshney MK, Trikha V, Khan SA, Choudhury B, Safaya R: \u003cb\u003eTreatment of aneurysmal bone cysts with percutaneous sclerotherapy using polidocanol. A review of 72 cases with long-term follow-up\u003c/b\u003e. J Bone Joint Surg Br 2006, \u003cb\u003e88\u003c/b\u003e(9):1212\u0026ndash;1216.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharifah M, Nurhazla H, Suraya A, Tan S: \u003cb\u003ePelvic aneurysmal bone cyst\u003c/b\u003e. Biomed Imaging Interv J 2011, \u003cb\u003e7\u003c/b\u003e(4):e24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNtalos D, Priemel M, Schlickewei C, Thiesen DM, Rueger JM, Spiro AS: \u003cb\u003eTherapeutic Management of a Substantial Pelvic Aneurysmatic Bone Cyst Including the Off-Label Use of Denosumab in a 35-Year-Old Female Patient\u003c/b\u003e. Case Rep Orthop 2017, \u003cb\u003e2017\u003c/b\u003e:9125493.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePapagelopoulos PJ, Choudhury SN, Frassica FJ, Bond JR, Unni KK, Sim FH: \u003cb\u003eTreatment of aneurysmal bone cysts of the pelvis and sacrum\u003c/b\u003e. J Bone Joint Surg Am 2001, \u003cb\u003e83\u003c/b\u003e(11):1674\u0026ndash;1681.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRastogi S, Varshney MK, Trikha V, Khan SA, Choudhury B, Safaya R: \u003cb\u003eTreatment of aneurysmal bone cysts with percutaneous sclerotherapy using polidocanol\u003c/b\u003e. The Journal of Bone and Joint Surgery British \u003cem\u003evolume\u003c/em\u003e 2006, \u003cb\u003e88-B\u003c/b\u003e(9):1212\u0026ndash;1216.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBatisse F, Schmitt A, Vendeuvre T, Herbreteau D, Bonnard C: \u003cb\u003eAneurysmal bone cyst: A 19-case series managed by percutaneous sclerotherapy\u003c/b\u003e. Orthop Traumatol Surg Res 2016, \u003cb\u003e102\u003c/b\u003e(2):213\u0026ndash;216.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrosjo O, Pechon P, Hesla A, Tsagozis P, Bauer H: \u003cb\u003eSclerotherapy with polidocanol for treatment of aneurysmal bone cysts\u003c/b\u003e. Acta Orthop 2013, \u003cb\u003e84\u003c/b\u003e(5):502\u0026ndash;505.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMasthoff M, Gerwing M, Schneider KN, Kohler M, Deventer N, Schindler P, Heindel W, Hardes J, Seidensticker M, Gosheger G \u003cem\u003eet al\u003c/em\u003e: \u003cb\u003eCombined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts\u003c/b\u003e. J Vasc Interv Radiol 2021, \u003cb\u003e32\u003c/b\u003e(10):1425\u0026ndash;1434 e1422.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVarshney MK, Rastogi S, Khan SA, Trikha V: \u003cb\u003eIs sclerotherapy better than intralesional excision for treating aneurysmal bone cysts?\u003c/b\u003e Clin Orthop Relat Res 2010, \u003cb\u003e468\u003c/b\u003e(6):1649\u0026ndash;1659.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLange T, Stehling C, Frohlich B, Klingenhofer M, Kunkel P, Schneppenheim R, Escherich G, Gosheger G, Hardes J, Jurgens H \u003cem\u003eet al\u003c/em\u003e: \u003cb\u003eDenosumab: a potential new and innovative treatment option for aneurysmal bone cysts\u003c/b\u003e. Eur Spine J 2013, \u003cb\u003e22\u003c/b\u003e(6):1417\u0026ndash;1422.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1: overview of the study collective\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003e\u003cstrong\u003egender\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e\u003cstrong\u003eage\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003e\u003cstrong\u003elocalization\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e\u003cstrong\u003evolume in cm\u003csup\u003e3\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEnneking classification\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003e\u003cstrong\u003eRastogi classification\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003e\u003cstrong\u003etreatment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e\u003cstrong\u003eresidual volume in cm\u003csup\u003e3\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003e\u003cstrong\u003eadditional treatment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e\u003cstrong\u003erecurrence/\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003epersistent\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003edisease\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003e\u003cstrong\u003enecessity of treatment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003e\u003cstrong\u003ecomplications\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e\u003cstrong\u003enumber of instilations\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003e\u003cstrong\u003esecond recurrence\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e\u003cstrong\u003efollow-up (months)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003esacrum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + PMMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003erecurrence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eischiium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + PMMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003erecurrence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e38,1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + bone substitute\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e11,9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + bone substitute\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003ebiopsy + watch and wait\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eischium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e45,7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003emarginal resection and reconstruction with PMMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003ehealing disorder\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003esacrum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003emarginal resection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e27,7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + bone substitute\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003erecurrence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e66,9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + PMMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003erecurrence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e136\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e222,6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003enot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eintralesional curettage + PMMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003ehealing disorder\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e43,8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eactive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003einstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e106\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e9,1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e40,1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e1,94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e20,2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e14,69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e51\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003epubis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e56,7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e31,27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003eilium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e113,3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eIII\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polidocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e58,98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"2.5588536335721597%\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.7082906857727735%\"\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"3.0706243602865917%\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.755373592630502%\"\u003e\n \u003cp\u003esacrum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"4.912998976458547%\"\u003e\n \u003cp\u003e32,7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eaggressiv\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.471852610030706%\"\u003e\n \u003cp\u003eIV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003eInstillation of polydocanol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.220061412487206%\"\u003e\n \u003cp\u003e32,44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.164790174002047%\"\u003e\n \u003cp\u003eembolization\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003epersistent disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.267144319344934%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.881269191402252%\"\u003e\n \u003cp\u003enone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.36949846468782%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.550665301944729%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.857727737973388%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"aneurysmal bone cyst, polidocanol injection, polidocanol instillation ","lastPublishedDoi":"10.21203/rs.3.rs-1401862/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1401862/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBACKGROUND: \u003c/strong\u003eThe\u003cstrong\u003e \u003c/strong\u003eaneurysmal bone cyst (ABC) is a benign, but locally aggressive cystic lesion of the bone.\u0026nbsp;It usually occurs in the metaphysis of long bones of adolescents and young adults but can also affect the pelvis.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMETHODS: \u003c/strong\u003eThis single-center study is a retrospective review of 17 patients with primary ABCs of the pelvis. The patients were treated surgically, by polidocanol instillation and, in selected cases, transarterial embolization.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eRESULTS: \u003c/strong\u003e17 patients with the diagnosis of a primary ABC of the pelvis were included in the study. Six patients were male (35.3%) and eleven patients female (64.7%); the mean age was 17.6 (9-49) years. The mean follow-up time was 50.2 months (12-136 months). The most common location of manifestation was the pubis (6; 35.3%), followed by the ilium (6; 35.3%), the sacrum (3; 17.6%) and the ischium (2; 11.8%). Eight patients were treated by intralesional curettage with the use of adjuvants, one patient by marginal resection, seven by sequential instillation of polidocanol and one patient by simple observation. Five patients received an additional transarterial embolization. After intralesional curettage local recurrence was detected in 4/8 cases (50%). After instillation therapy six patients (85.7%) had a stable disease without recurrence, only one patient (14.3%) had a persistent disease with need of additional treatment and was therefore converted to intralesional curettage without local recurrence in the follow-up.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCONCLUSIONS: \u003c/strong\u003eSequential instillations of polidocanol are a promising, minimally invasive treatment method for ABCs of the pelvis and can be well combined with transarterial embolization.\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"Aneurysmal Bone Cyst of the Pelvis: a single-center study of 17 cases","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-03-16 18:47:59","doi":"10.21203/rs.3.rs-1401862/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2022-03-23T03:16:50+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-03-15T10:49:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"3c97e23b-2a5a-4463-9978-e4cb546445cf","date":"2022-03-15T10:07:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-03-15T10:02:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-03-15T10:01:14+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2022-03-15T05:28:14+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2022-03-15T05:22:46+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Musculoskeletal Disorders","date":"2022-02-27T22:55:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5884cbab-49c7-48d5-b8ab-6c66612ebd73","owner":[],"postedDate":"March 16th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2022-04-25T13:44:19+00:00","versionOfRecord":[],"versionCreatedAt":"2022-03-16 18:47:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1401862","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1401862","identity":"rs-1401862","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}