Combined Endoscopic and External Approach for Resection of a Large Ethmoido-Orbito-Frontal Osteoma in a Pediatric Patient: A Surgical Challenge

Combined Endoscopic and External Approach for Resection of a Large Ethmoido-Orbito-Frontal Osteoma in a Pediatric Patient: A Surgical Challenge | 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 Case Report Combined Endoscopic and External Approach for Resection of a Large Ethmoido-Orbito-Frontal Osteoma in a Pediatric Patient: A Surgical Challenge Mohammed Rami, Mohamed Chehbouni, Salah-eddine Youbi, Omar Oulghoul, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8845702/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Osteomas are benign, slow-growing tumors commonly found in the paranasal sinuses. While typically asymptomatic, large osteomas that extend into the orbit or skull base present significant surgical challenges, particularly in pediatric patients. A combined endoscopic and external approach is often required for safe resection in such cases. Case Presentation : A 15-year-old female presented with a 4-month history of right-sided non-axial exophthalmos, with no associated symptoms such as ocular pain, nasal obstruction, or neurological deficits. Imaging studies, including CT and MRI, revealed a large ethmoidal osteoma extending into the orbit and the right frontal sinus. The lesion measured approximately 22 × 19 × 24 mm and caused mild displacement of the right globe. Due to the tumor’s location and extension into critical structures, a combined endoscopic and external surgical approach was employed. The procedure involved an endoscopic endonasal resection followed by an external approach through an incision at the internal canthus for complete excision of the orbital portion. Postoperative recovery was uneventful, and the patient showed significant improvement in exophthalmos without any complications. Conclusion Large osteomas of the ethmoid and frontal sinuses, especially those extending into the orbit or skull base, present significant surgical challenges. In such cases, a combined endoscopic and external approach is essential for achieving complete resection while minimizing morbidity and preserving function. This case underscores the importance of a multidisciplinary approach in managing complex sinonasal osteomas in pediatric patients. Early diagnosis, careful preoperative planning, and appropriate surgical techniques are crucial for optimal outcomes. This case adds to the growing evidence supporting the use of combined surgical approaches for managing large, complex osteomas in anatomically sensitive areas. osteoma ethmoid sinus orbit pediatric surgical approach endoscopic external exophthalmos resection skull base Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Osteomas are benign, slow-growing bone tumors that arise from the craniofacial skeleton and are most commonly found in the paranasal sinuses, particularly the frontal and ethmoid sinuses (Perez et al., 2020 ). In most cases, these lesions are discovered incidentally during imaging studies performed for unrelated reasons. However, when osteomas enlarge or extend beyond the boundaries of the paranasal sinuses, they may become symptomatic due to compression of adjacent structures, including the orbit, anterior skull base, or sinonasal drainage pathways (Rami et al., 2025 ). Paranasal sinus osteomas are uncommon in the pediatric population, and their management presents unique challenges related to ongoing craniofacial growth, narrower anatomical corridors, and close proximity to critical neuro-ophthalmologic structures (Lee et al., 2022 ). Large ethmoidal or frontoethmoidal osteomas with orbital or skull base extension are particularly complex and may result in exophthalmos, visual disturbances, diplopia, or, in rare cases, intracranial complications. In such situations, meticulous preoperative evaluation and careful selection of the surgical approach are essential to minimize morbidity and preserve function. Advances in endoscopic endonasal techniques have significantly expanded the indications for minimally invasive management of sinonasal osteomas. Endoscopic approaches are now considered the treatment of choice for small to moderately sized lesions confined to the ethmoid sinus or frontal recess, offering reduced soft tissue disruption and faster postoperative recovery (Singh et al., 2024 ). Nevertheless, when osteomas are large, anteriorly located, or extend into the orbit or anterior cranial fossa, an exclusively endoscopic approach may be insufficient to achieve safe and complete resection. In such cases, combined endoscopic and external approaches provide improved exposure and greater surgical control (Zhang et al., 2022 ). This report describes a rare case of a large ethmoido-orbito-frontal osteoma in a 15-year-old female patient successfully managed using a combined endoscopic and external surgical approach. The aim of this case report is to highlight the surgical decision-making process, technical considerations, and specific challenges associated with the management of extensive sinonasal osteomas in pediatric patients, and to emphasize the role of combined approaches in achieving optimal clinical outcomes. Case presentation A 15-year-old female with no relevant medical history presented with a 4-month history of right-sided non-axial exophthalmos. She reported no associated symptoms such as ocular pain, nasal obstruction, epistaxis, or anosmia. There were no signs of headaches, visual disturbances, or neurological deficits. On ENT examination, the nasal mucosa appeared healthy, with no septal deviation or signs of inflammation. The oral cavity was unremarkable, and there were no masses or lesions. No tenderness was noted on palpation of the orbital or paranasal areas, and there were no palpable lymph nodes or masses. (A) Frontal view showing non-axial protrusion of the right eye. (B) Right lateral profile view demonstrating evident right-sided exophthalmos. (C) Left lateral profile view showing normal globe position for comparison Ophthalmological examination revealed right-sided exophthalmos that was non-axial and non-reducible. There were no abnormalities in ocular movement, and visual field testing was normal. Visual acuity was intact (Fig. 1 ). Neurological examination revealed no deficits, and the patient showed no signs of systemic illness. Overall, the clinical findings suggested a localized condition affecting the right orbit, without evidence of systemic or neurological involvement. Facial computed tomography revealed a well-defined osseous lesion centered on the anterior and middle right ethmoidal cells, measuring approximately 22 × 19 × 24 mm. The lesion had a roughly oval shape and exhibited dense bone attenuation. Superiorly and posteriorly, it extended to contact the right cribriform plate, the orbital surface of the frontal bone, and the posterior wall of the right frontal sinus, without evidence of bone lysis. Laterally, the lesion protruded into the right orbital cavity, coming into contact with the medial rectus muscle, with focal loss of the normal fat plane of separation. It displaced the posteromedial quadrant of the right globe, while preserving its sphericity, and respected the intra- and extraconal orbital fat. The lesion was associated with a grade I ipsilateral exophthalmos. The right frontal sinus showed partial occupation. The cavernous sinuses were normally opacified, and no additional osseous lesions were identified. The left globe and remaining paranasal sinuses were unremarkable, aside from bilateral concha bullosa, more pronounced on the right, and mucosal thickening of the inferior turbinate (Fig. 2 ). (A) Axial CT scan showing a well-defined hyperdense osseous lesion arising from the right ethmoidal cells with extension into the medial orbital cavity. (B) Coronal CT scan demonstrating superior extension toward the right frontal sinus and the anterior skull base. (C) Sagittal CT scan highlighting the significant intraorbital component of the osteoma with displacement of the right globe The orbital MRI revealed a lesion centered in the right anterior ethmoidal cells, measuring 23 × 20 mm. The lesion showed a heterogeneous signal on both T1 and T2 sequences. It extended into the right frontal sinus and the internal wall of the right orbit, compressing the medial rectus muscle and the globe, contributing to the right-sided grade I exophthalmos. There was no involvement of the left orbit or sinuses, and the surrounding fat and muscle structures were preserved on that side. The cerebral MRI was unremarkable, with normal morphology of the brain parenchyma, ventricular system, and cerebellar angles. No masses or abnormalities were observed in the acoustic-facial bundles or other regions. The patient, under general anesthesia, underwent a combined endoscopic (Figs. 3 and 4 ) and external surgical approach (Fig. 5 ) for the removal of a large ethmoido-orbito-frontal osteoma. The procedure began with packing and decongestion of the nasal cavities using xylocaine naphazoline. The first step involved an endoscopic endonasal approach to remove as much of the tumor as possible. Anterior ethmoidectomy was performed to expose the osteoma, followed by a middle meatal antrostomy to identify the level of the right orbital medial wall. A posterior ethmoidectomy was then performed to expose the posterior ethmoid and base of the skull, enabling a clear view for resection. The mucosa covering the osteoma on the medial ethmoidal wall was carefully opened and raised as a lower hinge flap, which would be repositioned after the osteoma’s excision. (B) Elevation of a mucosal flap with an inferior hinge along the medial orbital wall to allow adequate exposure of the osteoma. (C) Drilling phase of the osteoma. (D) Removal of the major endonasal portion of the osteoma, with preservation of a thin residual bony shell to protect the orbital contents, which was subsequently removed by controlled fracture using a periosteal elevator. Abbreviations : O , osteoma; S , nasal septum; Or , orbit; F , mucosal flap; AE , anterior ethmoidal cells; PE , posterior ethmoidal cells. The osteoma was then drilled along the base of the skull, the posterior ethmoid, and the posterior component of the tumor, which was bulging into the posterior orbital area. The dissection continued until the orbital fat was reached. Due to difficulty accessing the anterior orbital portion of the osteoma through the endonasal approach, a decision was made to perform an external approach. An incision was made at the internal canthus. The subperiosteal dissection of the orbital contents was performed to expose the remaining osteoma. The orbital cavity and any remaining tumor residue were then identified and resected. The anterior portion of the osteoma was drilled further to achieve subtotal excision, significantly reducing the exophthalmos (Fig. 6 A). Once the excision was completed, the mucosal flap was repositioned, and a Silastic plate was placed between the flap and the nasal septum to prevent adhesion. The surgical site was then packed, and the external incision was closed. During recovery, all ventilation through a mask was strictly prohibited, and no Valsalva maneuvers were allowed to avoid potential complications such as pneumo-orbite. The patient was maintained on parenteral antibiotics, corticosteroids, antitussives, and laxatives to control pain and prevent postoperative complications. The postoperative course was uneventful, with no clinical or radiological evidence of pneumo-orbite or other ophthalmological or neurological complications. The patient was discharged on postoperative day 2 (Fig. 6 B) and subsequently evaluated at 48 hours and 1 week postoperatively, at which time a control computed tomography (CT) scan confirmed satisfactory surgical outcomes with subtotal removal of the osteoma (Fig. 7 ). Additional follow-up visits were conducted at 15 days (Fig. 6 C) and 1 month postoperatively, all of which demonstrated a favorable clinical evolution, with significant improvement in palpebral swelling and marked reduction of exophthalmos. Definitive Pathology The final histopathological analysis confirmed the presence of an osteoma. (A) Axial CT image and (B) coronal CT image demonstrating resection of the intraorbital component of the osteoma and near-complete removal of the endonasal component, with restoration of normal orbital anatomy and no evidence of residual mass effect. Discussion Paranasal sinus osteomas are benign, slow-growing bone-forming tumors that arise from the craniofacial skeleton and most commonly involve the frontal and ethmoid sinuses (Perez et al., 2020 ). Although their exact etiology remains unclear, several hypotheses have been proposed, including embryologic developmental anomalies, chronic inflammation, trauma, and genetic factors. Comprehensive narrative reviews have further emphasized the multifactorial origin of these lesions and proposed grading systems to guide management (Sofokleous et al., 2021 ). Most osteomas remain clinically silent for many years and are frequently detected incidentally during radiologic examinations (Değer et al., 2022 ). Surgical intervention is generally reserved for symptomatic lesions, those demonstrating progressive growth, or osteomas extending toward critical anatomical structures such as the orbit or anterior skull base (Rami et al., 2025 ). Ethmoidal and frontoethmoidal osteomas represent a distinct subset because of their close anatomical relationship with the orbit and skull base. As these lesions enlarge, they may cause orbital displacement, exophthalmos, diplopia, visual disturbances, or, more rarely, intracranial complications. Severe complications such as subdural empyema have been reported in association with giant fronto-ethmoidal osteomas, underscoring the importance of timely management (Benzagmout et al., 2020 ). Similarly, cases with significant intracranial and orbital extension highlight the potential aggressiveness of otherwise histologically benign tumors (Dari and Gdey, 2024 ). In such cases, timely surgical management is essential to prevent irreversible functional impairment. High-resolution computed tomography remains the imaging modality of choice for defining tumor extent, bony attachment, and relationships with adjacent structures (Guo et al., 2024 ), whereas magnetic resonance imaging is particularly useful for evaluating orbital and intracranial soft-tissue involvement (Lee et al., 2022 ). The advent of endoscopic endonasal surgery has significantly expanded the therapeutic options for the management of paranasal sinus osteomas. Endoscopic techniques are now widely accepted as the first-line approach for small to moderately sized lesions confined to the ethmoid sinus or frontal recess, offering excellent visualization, reduced soft-tissue trauma, and faster postoperative recovery (Singh et al., 2024 ). Institutional experiences have demonstrated that endoscopic approaches can achieve favorable outcomes with low morbidity when lesions are appropriately selected (Lim et al., 2020 ; Değer et al., 2022 ). With advances in optics, instrumentation, and navigation systems, many lesions previously managed through external approaches can now be treated endoscopically with comparable outcomes (Minni et al., 2023 ). However, the limitations of a purely endoscopic approach become evident in the management of large or “giant” osteomas, particularly those exceeding 30 mm in diameter or extending into the orbit or anterior cranial fossa. Restricted access to anterior, lateral, or intraorbital components may compromise the completeness and safety of endoscopic resection. Case reports describing persistent postoperative discomfort despite complete removal further highlight the complexity of managing extensive lesions (Aburas et al., 2022 ). In such situations, combined endoscopic and external approaches offer complementary advantages, allowing surgeons to benefit from endoscopic visualization while achieving direct access to areas that are otherwise difficult to reach through the nasal corridor alone (Zhang et al., 2022 ). Innovative combined techniques, including transconjunctival and endoscopic approaches, have also demonstrated safe management of orbitally extending lesions (Suwa et al., 2024 ). The pediatric population presents additional challenges in this context. Ongoing craniofacial development, narrower anatomical corridors, and increased concern for functional and aesthetic preservation necessitate a particularly cautious surgical strategy (Lee et al., 2022 ). Pediatric-specific radiologic and surgical considerations have been emphasized in recent literature, reinforcing the importance of individualized planning. Recurrence remains uncommon overall, but systematic reviews stress that adequate resection and long-term follow-up are essential, particularly in younger patients (Szyfter et al., 2022 ). In the present case, the osteoma produced clinically evident nonaxial exophthalmos due to significant intraorbital extension. While the endoscopic endonasal approach allowed effective resection of the ethmoidal and posterior components of the tumor, access to the anterior orbital portion was limited. The decision to proceed with a supplemental external medial canthal approach enabled safe exposure and controlled drilling of the residual lesion, resulting in marked clinical improvement without complications. Similar external or combined strategies have been advocated for massive ethmoido-orbital osteomas where endoscopic exposure alone is insufficient (Rami et al., 2025 ; Zhang et al., 2022 ). Several studies and systematic analyses have reported favorable outcomes with combined approaches in comparable scenarios, emphasizing their role in achieving complete or near-complete resection while preserving orbital and neurologic function (Zhang et al., 2022 ; Szyfter et al., 2022 ; Minni et al., 2023 ). Importantly, complication rates associated with combined approaches remain low when performed by experienced surgical teams, and recurrence is uncommon when adequate tumor removal is achieved (Lim et al., 2020 ). These findings underscore the importance of tailoring the surgical strategy to the individual patient rather than adhering rigidly to a single technique. The decision-making process in osteoma surgery should therefore be guided by multiple factors, including tumor size, location, extent, relationship to critical structures, and surgeon experience. Radiologically guided surgical planning plays a central role in approach selection (Guo et al., 2024 ). Multidisciplinary collaboration among otolaryngologists, ophthalmologists, radiologists, and, when necessary, neurosurgeons is particularly valuable in complex cases involving orbital or skull base extension. Such collaboration enhances preoperative planning, intraoperative safety, and postoperative outcomes. This case contributes to the growing body of evidence supporting the use of combined endoscopic and external approaches for the management of large, complex paranasal sinus osteomas. In pediatric patients, where functional preservation and long-term outcomes are paramount, a flexible and individualized surgical strategy is essential. Combined approaches offer a safe and effective solution when endoscopic access alone is insufficient, ensuring optimal tumor control while minimizing morbidity. Conclusion Large ethmoido-orbito-frontal osteomas in pediatric patients are rare and pose significant surgical challenges because of their proximity to critical orbital and skull base structures. This case demonstrates that a combined endoscopic and external approach allows safe and effective resection when endoscopic access alone is insufficient. Careful preoperative imaging, tailored surgical planning, and multidisciplinary collaboration are essential to achieve optimal functional and anatomical outcomes while minimizing morbidity in complex sinonasal osteomas. Declarations Ethics approval and consent to participate This case report was conducted in accordance with the principles of the Declaration of Helsinki. In accordance with institutional policy, formal ethics committee approval was not required for the retrospective description of a single clinical case involving no identifiable personal information and no experimental intervention. Written informed consent was obtained from the patient’s legal guardian. Consent for publication Written informed consent for publication of the clinical details and accompanying images was obtained from the patient’s legal guardian. Availability of data and material All data generated or analyzed during this study are included in this published article. Further information is available from the corresponding author upon reasonable request. Competing interests The authors declare that they have no competing interests. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors' contributions MR: Conceptualisation, surgical management, manuscript drafting. MC: Data collection and literature review. SY: Radiological analysis and interpretation. OO: Intraoperative assistance and data acquisition. YL: Postoperative follow-up and manuscript revision. YR: Supervision and critical revision of the manuscript. AR: Senior supervision, validation of surgical strategy, and final approval of the manuscript. Acknowledgements The authors thank the Department of Otolaryngology – Head and Neck Surgery, Mohammed VI University Hospital Center, Marrakech, for their support in the clinical management of this case. References Aburas S, Schneider B, Pfaffeneder-Mantai F, Meller O, Balensiefer A (2022) Long-term persistent discomfort due to a giant frontoethmoidal osteoma despite complete surgical removal: a case report. Annals Med Surg 78:103814. https://doi.org/10.1016/j.amsu.2022.103814 Benzagmout M, Lakhdar F, Chakour K, Chaoui MEF (2020) Subdural empyema complicating a giant fronto-ethmoidal osteoma. Asian J Neurosurg 15:737–740. https://doi.org/10.4103/ajns.AJNS_196_20 Dari MA, Gdey MM (2024) A case of giant fronto-ethmoidal osteoma (45 × 42 mm) with intracranial and orbital extension: a case report. J Med Case Rep 18:584. https://doi.org/10.1186/s13256-024-04953-x Değer HM, Bayrak BY, Mutlu F, Öztürk M (2022) Clinical experience and treatment approaches in sinonasal osteomas from a tertiary care hospital in Turkey. Auris Nasus Larynx 49:84–91. https://doi.org/10.1016/j.anl.2021.05.001 Guo M, Wu X, Yuan T, Wu S, Huang Z, Yang Q, Zhang G, Shi Z (2024) Based on CT imaging, surgical approach selection for frontal and ethmoid sinus osteoma. Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 38:523–529. https://doi.org/10.13201/j.issn.2096-7993.2024.06.013 Lee JY, Hong JH, Kim HJ et al (2022) Paediatric frontal sinus osteoma: radiologic features and surgical management. Pediatr Radiol 52:1256–1264. https://doi.org/10.1007/s00247-022-05379-5 Lim HR, Lee DH, Lim SC (2020) Surgical treatment of frontal sinus osteoma. Eur Arch Otorhinolaryngol 277:2469–2473. https://doi.org/10.1007/s00405-020-06021-8 Minni A, Roncoroni L, Cialente F, Zoccali F, Colizza A, Placentino A, Ormellese G, Ralli M, de Vincentiis M, Dragonetti A (2023) Surgical approach to frontal and ethmoid sinus osteomas: the experience of two metropolitan Italian hospitals. Ear Nose Throat J 102:720–726. https://doi.org/10.1177/01455613211016895 Perez RL, Smith BS, Prasad SC (2020) Epidemiology and clinical characteristics of paranasal sinus osteomas: an institutional series. Otolaryngology–Head Neck Surg 162:726–734. https://doi.org/10.1177/0194599820911578 Rami M et al (2025) External approach for massive ethmoido-orbital osteoma extraction: case report and review. Indian J Otolaryngol Head Neck Surg 77. https://doi.org/10.1007/s12070-025-05767-z Singh S, Patel VA, Bhattacharyya N (2024) Endoscopic techniques and navigation in osteoma resection. World J Otorhinolaryngology–Head Neck Surg 10:102–110. https://doi.org/10.1016/j.wjorl.2023.11.004 Sofokleous V, Maragoudakis P, Kyrodimos E, Giotakis E (2021) Management of paranasal sinus osteomas: a comprehensive narrative review of the literature and an up-to-date grading system. Am J Otolaryngol 42:102644. https://doi.org/10.1016/j.amjoto.2020.102644 Suwa T, Kitaguchi Y, Maeda Y, Morimoto T, Nishida K (2024) Combined upper fornix transconjunctival and endoscopic transnasal approach for frontoethmoidal osteoma with orbital extension: a case report. Annals Maxillofacial Surg 14:248–251. https://doi.org/10.4103/ams.ams_87_23 Szyfter W, Golusiński W, Wierzbicka M (2022) Recurrence rates after paranasal sinus osteoma surgery: a systematic review. Eur Arch Otorhinolaryngol 279:4423–4434. https://doi.org/10.1007/s00405-022-07329-7 Zhang L, Guo Z, Li X (2022) Combined endoscopic and external approaches for giant fronto-ethmoid osteomas. Int Forum Allergy Rhinology 12:1205–1212. https://doi.org/10.1002/alr.22979 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-8845702","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":597734561,"identity":"6b8c5bd8-5a77-4e96-b8fb-83a7b50f5603","order_by":0,"name":"Mohammed 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\u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(C)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Left lateral profile view showing normal globe position for comparison\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/fd49dddea58618db8dab6567.png"},{"id":104346102,"identity":"c2525e5b-c4c3-4acc-b0f0-7ad9464aa5f0","added_by":"auto","created_at":"2026-03-10 17:42:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1795713,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePreoperative facial computed tomography findings.\u003c/em\u003e\u003cbr\u003e\n \u003cem\u003e\u003cstrong\u003e(A)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Axial CT scan showing a well-defined hyperdense osseous lesion arising from the right ethmoidal cells with extension into the medial orbital cavity.\u003cbr\u003e\n \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(B)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Coronal CT scan demonstrating superior extension toward the right frontal sinus and the anterior skull base.\u003cbr\u003e\n \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(C)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Sagittal CT scan highlighting the significant intraorbital component of the osteoma with displacement of the right globe\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/1efcb9dc9a42bfa8e686f2b7.png"},{"id":104405569,"identity":"8261ee5d-0e42-47ac-b540-173315a31cc3","added_by":"auto","created_at":"2026-03-11 12:23:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":2304341,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eEndoscopic endonasal intraoperative views of the right nasal cavity during osteoma resection.\u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(A)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Surgical field after posterior ethmoidectomy allowing identification and preservation of the skull base, followed by anterior ethmoidectomy to expose the osteoma.\u003cbr\u003e\n \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(B)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Elevation of a mucosal flap with an inferior hinge along the medial orbital wall to allow adequate exposure of the osteoma.\u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(C)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003eDrilling phase of the osteoma.\u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(D)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Removal of the major endonasal portion of the osteoma, with preservation of a thin residual bony shell to protect the orbital contents, which was subsequently removed by controlled fracture using a periosteal elevator.\u003c/em\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e: \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eO\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, osteoma; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eS\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, nasal septum; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eOr\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, orbit; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eF\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, mucosal flap; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eAE\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, anterior ethmoidal cells; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003ePE\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, posterior ethmoidal cells.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/09256b14d617aa9e8468c1df.png"},{"id":104406163,"identity":"c6643336-3856-4a45-a5c6-5d60355f8a37","added_by":"auto","created_at":"2026-03-11 12:24:57","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1101834,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eFour-hand endoscopic surgical technique illustrating the technical complexity of osteoma resection: Intraoperative view showing the main surgeon holding the endoscope and drilling the osteoma, while the first assistant provides continuous irrigation with physiological saline and the second assistant performs suction of irrigation fluid and bone debris to maintain optimal visualization of the surgical field\u003c/em\u003e.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/f490b531c54495a0b8129b06.png"},{"id":104346107,"identity":"717fc7d4-d25c-487e-aebd-decc30aeebcc","added_by":"auto","created_at":"2026-03-10 17:42:13","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":2239946,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eExternal surgical approach for resection of the anterior orbital component of the osteoma. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(A)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003eMedial canthal incision providing access to the anterior orbital component of the tumor. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(B)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Drilling of the anterior component of the osteoma after elevation of the periorbital contents, protected with a metallic retractor. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(C)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Endoscopic view obtained through the external incision after resection of the anterior portion of the osteoma, showing exposure of the periorbital fat. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(D)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Same view after coagulation of the periorbital fat. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e: \u003c/em\u003e\u003cem\u003e\u003cstrong\u003ePF\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, periorbital fat; \u003c/em\u003e\u003cem\u003e\u003cstrong\u003erO\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e, residual osteoma.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/775a90b0a7db7973ae2aec52.png"},{"id":104346108,"identity":"3a829fae-0387-47f8-ba18-deb629e4b8f4","added_by":"auto","created_at":"2026-03-10 17:42:13","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":1206039,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePostoperative clinical outcome following combined surgical resection. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(A)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003eImmediate postoperative frontal view showing marked reduction of the right-sided exophthalmos. \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(B)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Frontal view two days after surgery demonstrating sustained improvement in ocular symmetry\u003c/em\u003e.\u003cem\u003e\u003cstrong\u003e (C) results 15j post-operative.\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/f249abab83bbe56018372b30.png"},{"id":104346106,"identity":"2e10992f-a185-48ec-9daf-68e2c38abdaa","added_by":"auto","created_at":"2026-03-10 17:42:13","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":869109,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003ePostoperative facial computed tomography at one-week follow-up.\u003cbr\u003e\n \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(A)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e Axial CT image and \u003c/em\u003e\u003cem\u003e\u003cstrong\u003e(B)\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e coronal CT image demonstrating resection of the intraorbital component of the osteoma and near-complete removal of the endonasal component, with restoration of normal orbital anatomy and no evidence of residual mass effect.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/18b752d8e719a674d5a1f9b2.png"},{"id":107705469,"identity":"2f48e2f3-dc07-4ed0-9c59-d79f981b4dab","added_by":"auto","created_at":"2026-04-24 09:13:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":20261993,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8845702/v1/125312b4-54a2-409c-9bd8-bfece02b2ad0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Combined Endoscopic and External Approach for Resection of a Large Ethmoido-Orbito-Frontal Osteoma in a Pediatric Patient: A Surgical Challenge","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOsteomas are benign, slow-growing bone tumors that arise from the craniofacial skeleton and are most commonly found in the paranasal sinuses, particularly the frontal and ethmoid sinuses (Perez et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In most cases, these lesions are discovered incidentally during imaging studies performed for unrelated reasons. However, when osteomas enlarge or extend beyond the boundaries of the paranasal sinuses, they may become symptomatic due to compression of adjacent structures, including the orbit, anterior skull base, or sinonasal drainage pathways (Rami et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2025\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eParanasal sinus osteomas are uncommon in the pediatric population, and their management presents unique challenges related to ongoing craniofacial growth, narrower anatomical corridors, and close proximity to critical neuro-ophthalmologic structures (Lee et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Large ethmoidal or frontoethmoidal osteomas with orbital or skull base extension are particularly complex and may result in exophthalmos, visual disturbances, diplopia, or, in rare cases, intracranial complications. In such situations, meticulous preoperative evaluation and careful selection of the surgical approach are essential to minimize morbidity and preserve function.\u003c/p\u003e \u003cp\u003eAdvances in endoscopic endonasal techniques have significantly expanded the indications for minimally invasive management of sinonasal osteomas. Endoscopic approaches are now considered the treatment of choice for small to moderately sized lesions confined to the ethmoid sinus or frontal recess, offering reduced soft tissue disruption and faster postoperative recovery (Singh et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Nevertheless, when osteomas are large, anteriorly located, or extend into the orbit or anterior cranial fossa, an exclusively endoscopic approach may be insufficient to achieve safe and complete resection. In such cases, combined endoscopic and external approaches provide improved exposure and greater surgical control (Zhang et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis report describes a rare case of a large ethmoido-orbito-frontal osteoma in a 15-year-old female patient successfully managed using a combined endoscopic and external surgical approach. The aim of this case report is to highlight the surgical decision-making process, technical considerations, and specific challenges associated with the management of extensive sinonasal osteomas in pediatric patients, and to emphasize the role of combined approaches in achieving optimal clinical outcomes.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 15-year-old female with no relevant medical history presented with a 4-month history of right-sided non-axial exophthalmos. She reported no associated symptoms such as ocular pain, nasal obstruction, epistaxis, or anosmia. There were no signs of headaches, visual disturbances, or neurological deficits.\u003c/p\u003e \u003cp\u003eOn ENT examination, the nasal mucosa appeared healthy, with no septal deviation or signs of inflammation. The oral cavity was unremarkable, and there were no masses or lesions. No tenderness was noted on palpation of the orbital or paranasal areas, and there were no palpable lymph nodes or masses.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(A)\u003c/b\u003e \u003cem\u003eFrontal view showing non-axial protrusion of the right eye.\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(B)\u003c/b\u003e \u003cem\u003eRight lateral profile view demonstrating evident right-sided exophthalmos.\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(C)\u003c/b\u003e \u003cem\u003eLeft lateral profile view showing normal globe position for comparison\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eOphthalmological examination revealed right-sided exophthalmos that was non-axial and non-reducible. There were no abnormalities in ocular movement, and visual field testing was normal. Visual acuity was intact (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eNeurological examination revealed no deficits, and the patient showed no signs of systemic illness. Overall, the clinical findings suggested a localized condition affecting the right orbit, without evidence of systemic or neurological involvement.\u003c/p\u003e \u003cp\u003eFacial computed tomography revealed a well-defined osseous lesion centered on the anterior and middle right ethmoidal cells, measuring approximately 22 \u0026times; 19 \u0026times; 24 mm. The lesion had a roughly oval shape and exhibited dense bone attenuation. Superiorly and posteriorly, it extended to contact the right cribriform plate, the orbital surface of the frontal bone, and the posterior wall of the right frontal sinus, without evidence of bone lysis. Laterally, the lesion protruded into the right orbital cavity, coming into contact with the medial rectus muscle, with focal loss of the normal fat plane of separation. It displaced the posteromedial quadrant of the right globe, while preserving its sphericity, and respected the intra- and extraconal orbital fat. The lesion was associated with a grade I ipsilateral exophthalmos. The right frontal sinus showed partial occupation. The cavernous sinuses were normally opacified, and no additional osseous lesions were identified. The left globe and remaining paranasal sinuses were unremarkable, aside from bilateral concha bullosa, more pronounced on the right, and mucosal thickening of the inferior turbinate (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(A)\u003c/b\u003e \u003cem\u003eAxial CT scan showing a well-defined hyperdense osseous lesion arising from the right ethmoidal cells with extension into the medial orbital cavity.\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(B)\u003c/b\u003e \u003cem\u003eCoronal CT scan demonstrating superior extension toward the right frontal sinus and the anterior skull base.\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003e(C)\u003c/b\u003e \u003cem\u003eSagittal CT scan highlighting the significant intraorbital component of the osteoma with displacement of the right globe\u003c/em\u003e\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eThe orbital MRI revealed a lesion centered in the right anterior ethmoidal cells, measuring 23 \u0026times; 20 mm. The lesion showed a heterogeneous signal on both T1 and T2 sequences. It extended into the right frontal sinus and the internal wall of the right orbit, compressing the medial rectus muscle and the globe, contributing to the right-sided grade I exophthalmos. There was no involvement of the left orbit or sinuses, and the surrounding fat and muscle structures were preserved on that side.\u003c/p\u003e \u003cp\u003eThe cerebral MRI was unremarkable, with normal morphology of the brain parenchyma, ventricular system, and cerebellar angles. No masses or abnormalities were observed in the acoustic-facial bundles or other regions.\u003c/p\u003e \u003cp\u003eThe patient, under general anesthesia, underwent a combined endoscopic (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) and external surgical approach (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e) for the removal of a large ethmoido-orbito-frontal osteoma.\u003c/p\u003e \u003cp\u003eThe procedure began with packing and decongestion of the nasal cavities using xylocaine naphazoline. The first step involved an endoscopic endonasal approach to remove as much of the tumor as possible. Anterior ethmoidectomy was performed to expose the osteoma, followed by a middle meatal antrostomy to identify the level of the right orbital medial wall. A posterior ethmoidectomy was then performed to expose the posterior ethmoid and base of the skull, enabling a clear view for resection. The mucosa covering the osteoma on the medial ethmoidal wall was carefully opened and raised as a lower hinge flap, which would be repositioned after the osteoma\u0026rsquo;s excision.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003e(B)\u003c/b\u003e \u003cem\u003eElevation of a mucosal flap with an inferior hinge along the medial orbital wall to allow adequate exposure of the osteoma.\u003c/em\u003e\u003cb\u003e(C)\u003c/b\u003e \u003cem\u003eDrilling phase of the osteoma.\u003c/em\u003e\u003cb\u003e(D)\u003c/b\u003e \u003cem\u003eRemoval of the major endonasal portion of the osteoma, with preservation of a thin residual bony shell to protect the orbital contents, which was subsequently removed by controlled fracture using a periosteal elevator.\u003c/em\u003e\u003cb\u003eAbbreviations\u003c/b\u003e: \u003cb\u003eO\u003c/b\u003e, \u003cem\u003eosteoma;\u003c/em\u003e \u003cb\u003eS\u003c/b\u003e, \u003cem\u003enasal septum;\u003c/em\u003e \u003cb\u003eOr\u003c/b\u003e, \u003cem\u003eorbit;\u003c/em\u003e \u003cb\u003eF\u003c/b\u003e, \u003cem\u003emucosal flap;\u003c/em\u003e \u003cb\u003eAE\u003c/b\u003e, \u003cem\u003eanterior ethmoidal cells;\u003c/em\u003e \u003cb\u003ePE\u003c/b\u003e, \u003cem\u003eposterior ethmoidal cells.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe osteoma was then drilled along the base of the skull, the posterior ethmoid, and the posterior component of the tumor, which was bulging into the posterior orbital area. The dissection continued until the orbital fat was reached. Due to difficulty accessing the anterior orbital portion of the osteoma through the endonasal approach, a decision was made to perform an external approach.\u003c/p\u003e \u003cp\u003eAn incision was made at the internal canthus. The subperiosteal dissection of the orbital contents was performed to expose the remaining osteoma. The orbital cavity and any remaining tumor residue were then identified and resected. The anterior portion of the osteoma was drilled further to achieve subtotal excision, significantly reducing the exophthalmos (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA).\u003c/p\u003e \u003cp\u003eOnce the excision was completed, the mucosal flap was repositioned, and a Silastic plate was placed between the flap and the nasal septum to prevent adhesion. The surgical site was then packed, and the external incision was closed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eDuring recovery, all ventilation through a mask was strictly prohibited, and no Valsalva maneuvers were allowed to avoid potential complications such as pneumo-orbite. The patient was maintained on parenteral antibiotics, corticosteroids, antitussives, and laxatives to control pain and prevent postoperative complications. The postoperative course was uneventful, with no clinical or radiological evidence of pneumo-orbite or other ophthalmological or neurological complications. The patient was discharged on postoperative day 2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB) and subsequently evaluated at 48 hours and 1 week postoperatively, at which time a control computed tomography (CT) scan confirmed satisfactory surgical outcomes with subtotal removal of the osteoma (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). Additional follow-up visits were conducted at 15 days (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC) and 1 month postoperatively, all of which demonstrated a favorable clinical evolution, with significant improvement in palpebral swelling and marked reduction of exophthalmos.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eDefinitive Pathology\u003c/strong\u003e \u003cp\u003eThe final histopathological analysis confirmed the presence of an osteoma.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003e(A)\u003c/b\u003e \u003cem\u003eAxial CT image and\u003c/em\u003e \u003cb\u003e(B)\u003c/b\u003e \u003cem\u003ecoronal CT image demonstrating resection of the intraorbital component of the osteoma and near-complete removal of the endonasal component, with restoration of normal orbital anatomy and no evidence of residual mass effect.\u003c/em\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eParanasal sinus osteomas are benign, slow-growing bone-forming tumors that arise from the craniofacial skeleton and most commonly involve the frontal and ethmoid sinuses (Perez et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Although their exact etiology remains unclear, several hypotheses have been proposed, including embryologic developmental anomalies, chronic inflammation, trauma, and genetic factors. Comprehensive narrative reviews have further emphasized the multifactorial origin of these lesions and proposed grading systems to guide management (Sofokleous et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Most osteomas remain clinically silent for many years and are frequently detected incidentally during radiologic examinations (Değer et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Surgical intervention is generally reserved for symptomatic lesions, those demonstrating progressive growth, or osteomas extending toward critical anatomical structures such as the orbit or anterior skull base (Rami et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2025\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEthmoidal and frontoethmoidal osteomas represent a distinct subset because of their close anatomical relationship with the orbit and skull base. As these lesions enlarge, they may cause orbital displacement, exophthalmos, diplopia, visual disturbances, or, more rarely, intracranial complications. Severe complications such as subdural empyema have been reported in association with giant fronto-ethmoidal osteomas, underscoring the importance of timely management (Benzagmout et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Similarly, cases with significant intracranial and orbital extension highlight the potential aggressiveness of otherwise histologically benign tumors (Dari and Gdey, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). In such cases, timely surgical management is essential to prevent irreversible functional impairment. High-resolution computed tomography remains the imaging modality of choice for defining tumor extent, bony attachment, and relationships with adjacent structures (Guo et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), whereas magnetic resonance imaging is particularly useful for evaluating orbital and intracranial soft-tissue involvement (Lee et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe advent of endoscopic endonasal surgery has significantly expanded the therapeutic options for the management of paranasal sinus osteomas. Endoscopic techniques are now widely accepted as the first-line approach for small to moderately sized lesions confined to the ethmoid sinus or frontal recess, offering excellent visualization, reduced soft-tissue trauma, and faster postoperative recovery (Singh et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Institutional experiences have demonstrated that endoscopic approaches can achieve favorable outcomes with low morbidity when lesions are appropriately selected (Lim et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Değer et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). With advances in optics, instrumentation, and navigation systems, many lesions previously managed through external approaches can now be treated endoscopically with comparable outcomes (Minni et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, the limitations of a purely endoscopic approach become evident in the management of large or \u0026ldquo;giant\u0026rdquo; osteomas, particularly those exceeding 30 mm in diameter or extending into the orbit or anterior cranial fossa. Restricted access to anterior, lateral, or intraorbital components may compromise the completeness and safety of endoscopic resection. Case reports describing persistent postoperative discomfort despite complete removal further highlight the complexity of managing extensive lesions (Aburas et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). In such situations, combined endoscopic and external approaches offer complementary advantages, allowing surgeons to benefit from endoscopic visualization while achieving direct access to areas that are otherwise difficult to reach through the nasal corridor alone (Zhang et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Innovative combined techniques, including transconjunctival and endoscopic approaches, have also demonstrated safe management of orbitally extending lesions (Suwa et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe pediatric population presents additional challenges in this context. Ongoing craniofacial development, narrower anatomical corridors, and increased concern for functional and aesthetic preservation necessitate a particularly cautious surgical strategy (Lee et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Pediatric-specific radiologic and surgical considerations have been emphasized in recent literature, reinforcing the importance of individualized planning. Recurrence remains uncommon overall, but systematic reviews stress that adequate resection and long-term follow-up are essential, particularly in younger patients (Szyfter et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the present case, the osteoma produced clinically evident nonaxial exophthalmos due to significant intraorbital extension. While the endoscopic endonasal approach allowed effective resection of the ethmoidal and posterior components of the tumor, access to the anterior orbital portion was limited. The decision to proceed with a supplemental external medial canthal approach enabled safe exposure and controlled drilling of the residual lesion, resulting in marked clinical improvement without complications. Similar external or combined strategies have been advocated for massive ethmoido-orbital osteomas where endoscopic exposure alone is insufficient (Rami et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Zhang et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSeveral studies and systematic analyses have reported favorable outcomes with combined approaches in comparable scenarios, emphasizing their role in achieving complete or near-complete resection while preserving orbital and neurologic function (Zhang et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Szyfter et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Minni et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Importantly, complication rates associated with combined approaches remain low when performed by experienced surgical teams, and recurrence is uncommon when adequate tumor removal is achieved (Lim et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). These findings underscore the importance of tailoring the surgical strategy to the individual patient rather than adhering rigidly to a single technique.\u003c/p\u003e \u003cp\u003eThe decision-making process in osteoma surgery should therefore be guided by multiple factors, including tumor size, location, extent, relationship to critical structures, and surgeon experience. Radiologically guided surgical planning plays a central role in approach selection (Guo et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Multidisciplinary collaboration among otolaryngologists, ophthalmologists, radiologists, and, when necessary, neurosurgeons is particularly valuable in complex cases involving orbital or skull base extension. Such collaboration enhances preoperative planning, intraoperative safety, and postoperative outcomes.\u003c/p\u003e \u003cp\u003eThis case contributes to the growing body of evidence supporting the use of combined endoscopic and external approaches for the management of large, complex paranasal sinus osteomas. In pediatric patients, where functional preservation and long-term outcomes are paramount, a flexible and individualized surgical strategy is essential. Combined approaches offer a safe and effective solution when endoscopic access alone is insufficient, ensuring optimal tumor control while minimizing morbidity.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eLarge ethmoido-orbito-frontal osteomas in pediatric patients are rare and pose significant surgical challenges because of their proximity to critical orbital and skull base structures. This case demonstrates that a combined endoscopic and external approach allows safe and effective resection when endoscopic access alone is insufficient. Careful preoperative imaging, tailored surgical planning, and multidisciplinary collaboration are essential to achieve optimal functional and anatomical outcomes while minimizing morbidity in complex sinonasal osteomas.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003eEthics approval and consent to participate\u003c/h3\u003e\n\u003cp\u003eThis case report was conducted in accordance with the principles of the Declaration of Helsinki. In accordance with institutional policy, formal ethics committee approval was not required for the retrospective description of a single clinical case involving no identifiable personal information and no experimental intervention. Written informed consent was obtained from the patient\u0026rsquo;s legal guardian.\u003c/p\u003e\n\u003ch3\u003eConsent for publication\u003c/h3\u003e\n\u003cp\u003eWritten informed consent for publication of the clinical details and accompanying images was obtained from the patient\u0026rsquo;s legal guardian.\u003c/p\u003e\n\u003ch3\u003eAvailability of data and material\u003c/h3\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article. Further information is available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003ch3\u003eCompeting interests\u003c/h3\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003ch3\u003eFunding\u003c/h3\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003ch3\u003eAuthors\u0026apos; contributions\u003c/h3\u003e\n\u003ch3\u003eMR: Conceptualisation, surgical management, manuscript drafting.\u003cbr\u003e\u0026nbsp;MC: Data collection and literature review.\u003cbr\u003e\u0026nbsp;SY: Radiological analysis and interpretation.\u003cbr\u003e\u0026nbsp;OO: Intraoperative assistance and data acquisition.\u003cbr\u003e\u0026nbsp;YL: Postoperative follow-up and manuscript revision.\u003cbr\u003e\u0026nbsp;YR: Supervision and critical revision of the manuscript.\u003cbr\u003e\u0026nbsp;AR: Senior supervision, validation of surgical strategy, and final approval of the manuscript.\u003c/h3\u003e\n\u003ch3\u003eAcknowledgements\u003c/h3\u003e\n\u003cp\u003eThe authors thank the Department of Otolaryngology \u0026ndash; Head and Neck Surgery, Mohammed VI University Hospital Center, Marrakech, for their support in the clinical management of this case.\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAburas S, Schneider B, Pfaffeneder-Mantai F, Meller O, Balensiefer A (2022) Long-term persistent discomfort due to a giant frontoethmoidal osteoma despite complete surgical removal: a case report. Annals Med Surg 78:103814. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.amsu.2022.103814\u003c/span\u003e\u003cspan address=\"10.1016/j.amsu.2022.103814\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenzagmout M, Lakhdar F, Chakour K, Chaoui MEF (2020) Subdural empyema complicating a giant fronto-ethmoidal osteoma. Asian J Neurosurg 15:737\u0026ndash;740. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4103/ajns.AJNS_196_20\u003c/span\u003e\u003cspan address=\"10.4103/ajns.AJNS_196_20\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDari MA, Gdey MM (2024) A case of giant fronto-ethmoidal osteoma (45 \u0026times; 42 mm) with intracranial and orbital extension: a case report. J Med Case Rep 18:584. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s13256-024-04953-x\u003c/span\u003e\u003cspan address=\"10.1186/s13256-024-04953-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeğer HM, Bayrak BY, Mutlu F, \u0026Ouml;zt\u0026uuml;rk M (2022) Clinical experience and treatment approaches in sinonasal osteomas from a tertiary care hospital in Turkey. Auris Nasus Larynx 49:84\u0026ndash;91. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.anl.2021.05.001\u003c/span\u003e\u003cspan address=\"10.1016/j.anl.2021.05.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuo M, Wu X, Yuan T, Wu S, Huang Z, Yang Q, Zhang G, Shi Z (2024) Based on CT imaging, surgical approach selection for frontal and ethmoid sinus osteoma. Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 38:523\u0026ndash;529. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.13201/j.issn.2096-7993.2024.06.013\u003c/span\u003e\u003cspan address=\"10.13201/j.issn.2096-7993.2024.06.013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee JY, Hong JH, Kim HJ et al (2022) Paediatric frontal sinus osteoma: radiologic features and surgical management. Pediatr Radiol 52:1256\u0026ndash;1264. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00247-022-05379-5\u003c/span\u003e\u003cspan address=\"10.1007/s00247-022-05379-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLim HR, Lee DH, Lim SC (2020) Surgical treatment of frontal sinus osteoma. Eur Arch Otorhinolaryngol 277:2469\u0026ndash;2473. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00405-020-06021-8\u003c/span\u003e\u003cspan address=\"10.1007/s00405-020-06021-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMinni A, Roncoroni L, Cialente F, Zoccali F, Colizza A, Placentino A, Ormellese G, Ralli M, de Vincentiis M, Dragonetti A (2023) Surgical approach to frontal and ethmoid sinus osteomas: the experience of two metropolitan Italian hospitals. Ear Nose Throat J 102:720\u0026ndash;726. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/01455613211016895\u003c/span\u003e\u003cspan address=\"10.1177/01455613211016895\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerez RL, Smith BS, Prasad SC (2020) Epidemiology and clinical characteristics of paranasal sinus osteomas: an institutional series. Otolaryngology\u0026ndash;Head Neck Surg 162:726\u0026ndash;734. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/0194599820911578\u003c/span\u003e\u003cspan address=\"10.1177/0194599820911578\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRami M et al (2025) External approach for massive ethmoido-orbital osteoma extraction: case report and review. Indian J Otolaryngol Head Neck Surg 77. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s12070-025-05767-z\u003c/span\u003e\u003cspan address=\"10.1007/s12070-025-05767-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh S, Patel VA, Bhattacharyya N (2024) Endoscopic techniques and navigation in osteoma resection. World J Otorhinolaryngology\u0026ndash;Head Neck Surg 10:102\u0026ndash;110. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.wjorl.2023.11.004\u003c/span\u003e\u003cspan address=\"10.1016/j.wjorl.2023.11.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSofokleous V, Maragoudakis P, Kyrodimos E, Giotakis E (2021) Management of paranasal sinus osteomas: a comprehensive narrative review of the literature and an up-to-date grading system. Am J Otolaryngol 42:102644. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.amjoto.2020.102644\u003c/span\u003e\u003cspan address=\"10.1016/j.amjoto.2020.102644\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuwa T, Kitaguchi Y, Maeda Y, Morimoto T, Nishida K (2024) Combined upper fornix transconjunctival and endoscopic transnasal approach for frontoethmoidal osteoma with orbital extension: a case report. Annals Maxillofacial Surg 14:248\u0026ndash;251. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4103/ams.ams_87_23\u003c/span\u003e\u003cspan address=\"10.4103/ams.ams_87_23\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSzyfter W, Golusiński W, Wierzbicka M (2022) Recurrence rates after paranasal sinus osteoma surgery: a systematic review. Eur Arch Otorhinolaryngol 279:4423\u0026ndash;4434. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00405-022-07329-7\u003c/span\u003e\u003cspan address=\"10.1007/s00405-022-07329-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang L, Guo Z, Li X (2022) Combined endoscopic and external approaches for giant fronto-ethmoid osteomas. Int Forum Allergy Rhinology 12:1205\u0026ndash;1212. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/alr.22979\u003c/span\u003e\u003cspan address=\"10.1002/alr.22979\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"osteoma, ethmoid sinus, orbit, pediatric, surgical approach, endoscopic, external, exophthalmos, resection, skull base","lastPublishedDoi":"10.21203/rs.3.rs-8845702/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8845702/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eOsteomas are benign, slow-growing tumors commonly found in the paranasal sinuses. While typically asymptomatic, large osteomas that extend into the orbit or skull base present significant surgical challenges, particularly in pediatric patients. A combined endoscopic and external approach is often required for safe resection in such cases.\u003c/p\u003e\u003ch2\u003eCase Presentation :\u003c/h2\u003e \u003cp\u003eA 15-year-old female presented with a 4-month history of right-sided non-axial exophthalmos, with no associated symptoms such as ocular pain, nasal obstruction, or neurological deficits. Imaging studies, including CT and MRI, revealed a large ethmoidal osteoma extending into the orbit and the right frontal sinus. The lesion measured approximately 22 \u0026times; 19 \u0026times; 24 mm and caused mild displacement of the right globe. Due to the tumor\u0026rsquo;s location and extension into critical structures, a combined endoscopic and external surgical approach was employed. The procedure involved an endoscopic endonasal resection followed by an external approach through an incision at the internal canthus for complete excision of the orbital portion. Postoperative recovery was uneventful, and the patient showed significant improvement in exophthalmos without any complications.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLarge osteomas of the ethmoid and frontal sinuses, especially those extending into the orbit or skull base, present significant surgical challenges. In such cases, a combined endoscopic and external approach is essential for achieving complete resection while minimizing morbidity and preserving function. This case underscores the importance of a multidisciplinary approach in managing complex sinonasal osteomas in pediatric patients. Early diagnosis, careful preoperative planning, and appropriate surgical techniques are crucial for optimal outcomes. This case adds to the growing evidence supporting the use of combined surgical approaches for managing large, complex osteomas in anatomically sensitive areas.\u003c/p\u003e","manuscriptTitle":"Combined Endoscopic and External Approach for Resection of a Large Ethmoido-Orbito-Frontal Osteoma in a Pediatric Patient: A Surgical Challenge","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-10 17:42:08","doi":"10.21203/rs.3.rs-8845702/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b9345df1-f726-4efa-b77e-ebe5ae4e5508","owner":[],"postedDate":"March 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T09:43:19+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-10 17:42:08","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8845702","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8845702","identity":"rs-8845702","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}