CASE REPORT: Pyomyositis in the Setting of Chemotherapy-Induced Pancytopenia: A Rare Complication of Germ Cell Tumour Treatment

CASE REPORT: Pyomyositis in the Setting of Chemotherapy-Induced Pancytopenia: A Rare Complication of Germ Cell Tumour Treatment | 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 CASE REPORT: Pyomyositis in the Setting of Chemotherapy-Induced Pancytopenia: A Rare Complication of Germ Cell Tumour Treatment Kaitlyn Trompert-Thompson, Amy Smith, Eugene Ang, Tyrone Soto, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8714688/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Apr, 2026 Read the published version in SN Comprehensive Clinical Medicine → Version 1 posted 11 You are reading this latest preprint version Abstract Introduction Spontaneous pyomyositis is an uncommon but serious infectious complication that typically occurs in immunocompromised patients and is more frequently reported in association with haematological malignancies. It’s occurrence in patients with solid organ tumours receiving systemic chemotherapy is rare and to date has not been described in the setting germ cell tumours. Case Presentation We report the case of a 50-year-old male with metastatic mixed germ cell tumour who developed pyomyositis following completion of four cycles of etoposide and cisplatin chemotherapy. Post-treatment, he developed severe pancytopenia complicated by fever, significant unilateral lower limb pain, and swelling. Initial imaging demonstrated multiple rim-enhancing intramuscular lesions, raising concern for metastatic disease versus abscess formation. Despite normalised tumour markers and no evidence of disease on restaging imaging, the radiological appearance remained equivocal. Image-guided biopsy and aspiration were therefore performed, yielding purulent material that cultured Staphylococcus aureus , with histopathology confirming benign inflammatory changes and no evidence of malignancy. The patient was successfully treated with oral antibiotics, with complete radiological resolution of lesions and no evidence of tumour relapse on follow-up. Conclusion This case represents, to our knowledge, the first reported instance of pyomyositis occurring in a patient with metastatic mixed germ cell tumour following chemotherapy. It highlights the importance of considering pyomyositis and spontaneous intramuscular haematoma as differential diagnoses in patients presenting with painful limb swelling in the setting of chemotherapy-induced pancytopenia, and underscores the diagnostic challenges in distinguishing infection from metastatic disease. Figures Figure 1 Figure 2 Figure 3 Introduction Pyomyositis is a rare complication of chemotherapy whereby severe pancytopenia can lead to the formation of haematomas secondary to spontaneous bleeding from thrombocytopenia and then development of abscesses and infection due to neutropenia. It is more commonly seen in haematological malignancies [ 1 ] albeit there are case reports in multiple solid organ malignancies [ 2 , 3 , 4 ]. However no research is available on case reports involving testicular germ cell tumours. It is cited in the literature that 47% of patients develop grade 3–4 neutropenia, with 2% developing grade 3–4 thrombocytopenia during the Etoposide and Cisplatin (EP) protocol for advanced or metastatic germ cell tumours [ 5 ]. As such, given the higher rates of cytopenia with systemic treatment for germ cell tumours, it is theoretically not unsurprising that this can occur. We report the case of a 50 year old male receiving EP for metastatic germ cell who developed pyomyositis post completion of treatment. Case Presentation A 50 year old male presented with right sided testicular pain and swelling and was found to a have tumour on ultrasound imaging. CT imaging revealed lymphadenopathy in the para-aortic nodes and several small pulmonary nodules bilaterally. He was previously otherwise well with no significant comorbidities other than a 20 pack/year smoking history. He underwent a right orchidectomy in April 2025 with histopathology revealing two tumours: Tumour 1: 30x25x23mm mixed germ cell tumour (yolk sac 80% and seminoma 20%) and Tumour 2: 40x30x16mm mixed germ cell tumour (embryonal 80% yolk sac 10%). He was recommended for 4 cycles of etoposide and cisplatin (bleomycin withheld due to smoking history and risk of pulmonary toxicities). He completed treatment with multiple Grade 1–2 toxicities including nausea, diarrhoea, insomnia and epistaxis. Post Cycle 4 he developed pancytopenia, with haemoglobin (Hb) 70 g/L, white cell count (WCC) 1.9 x10 9 /L, neutrophil count 1.3x10 9 /L and platelet (PLT) count 16x10 9 /L which required transfusion of 2 units of packed red blood cells. He subsequently developed fevers and lower limb pain with associated right leg swelling. He presented for review 17 days post last dose of EP (C4 D20) with significant lower limb swelling, particularly of the right leg which was extremely tender to touch and he experienced severe pain in the buttocks when seated. There was concern of potential extensive deep vein thrombosis or internal bleeding secondary to thrombocytopenia causing compartment syndrome. PL was subsequently admitted to hospital for further investigation and work up. CT Angiogram of the right lower limb demonstrated multiple rim-enhancing lesions in the gluteus, adductor magnus, biceps femoris and vastus medialis with subcutaneous fat stranding and oedema (Fig. 1 ). Differential diagnoses based on imaging included potential abscesses versus metastatic deposits. He was reviewed by the Orthopaedic surgical team who recommended MRI to further delineate the aetiology. MRI again demonstrated numerous rim-enhancing lesions with no internal diffusion restriction and marked muscular oedema. Findings were reported as more in keeping with metastases than abscesses. He underwent repeat staging CT Chest Abdomen and Pelvis which showed no evidence of other metastatic disease (Fig. 2 ). His tumour markers at this time had normalised (AFP 3 bHCG < 1 LDH 224). He subsequently underwent a biopsy of the right mid thigh region within the vastus intermedius muscle. Purulent fluid was aspirated and sent for culture, along with 5 core biopsies which were sent for culture and histopathology. Culture of the aspirate and tissue grew Staphylococcus Aureus. Both cytology and histopathology of the core biopsies revealed benign inflammatory tissue only with negative OCT-4 and CAM5.2 (Fig. 3 ). The Infectious Diseases team was consulted and they recommended oral cephalexin 1g four times a day for 2 weeks. Follow-up CT imaging performed 5 weeks after completed of antibiotics showed resolution of these collections. At the time of writing, the patient is clinically well with no evidence of relapsed mixed germ cell tumour on CT imaging. Discussion Pyomyositis remains a rare complication of chemotherapy, with a preponderance for haematological malignancies. There are twelve case reports of isolated occurrences in solid organ malignancies (Table 1 ), with two of these cases representing teratoma but no clearly documented cases in mixed germ cell tumours. To our knowledge, this case report thus serves as the first documented case of pyomyositis in metastatic mixed germ cell tumour. In the context of pancytopenia secondary to chemotherapy, we know the risk of infection and the possibility of sepsis is ever present and it is something patients are counselled on extensively. Spontaneous haematomas are much less common albeit documented in a number of case reports [ 6 , 7 , 8 , 9 ], as such it needs to remain a differential in our patients who present with painful swelling in the context of thrombocytopenia. Initial instinct is often to rule out deep vein thrombosis given the pro-thrombotic nature of both cancer and chemotherapy [ 10 ]. The difficulty in our case was the need to rule out metastatic disease, as radiologically it was unable to be excluded. In the context of normalised tumour markers post chemotherapy and a 5-year progression free survival rate of 96% [ 11 ] – the risk of metastatic disease was extremely low, however concern for seeding of the tumour with sampling of these lesions was raised by the sub-specialty teams involved. Given the unlikelihood of metastatic disease in the context of normal tumour markers and an otherwise normal restaging CT, a decision was made to proceed with radiologically guided biopsy and cytology. This confirmed Staph. Aureus pyomyositis in the right thigh, with no evidence of metastatic disease. Conclusion Systemic treatment for malignancies come with a vast array of side effects and toxicities. We extensively counsel patients on a number of these including the risk of infection. This case highlights that spontaneous haematomas and pyomyositis can be a complication of chemotherapy regimens that result in significant pancytopenia and thus need to remain a differential in patients who present with pain and swelling. Declarations Funding – not applicable Conflicts of interest – not applicable Ethics approval – not applicable Consent to participate – patient provided written consent Written consent for publication – patient provided Availability of data and material – not applicable Code availability – not applicable Authors contributions – Kaitlyn Trompert-Thompson was the primary author of the manuscript with assistance from Amy Smith. Amy Smith prepared figures 1 and 2. Eugene Ang prepared table 1. Tyrone Soto and Timothy Wade prepared figure 3. Amanda Stevanovic was the primary supervisor. All authors reviewed manuscript prior to submission. References Hayashi T, Nozaki M, Nonaka Y, Ohashi K, Sakamaki H, Nomura T. Pyomyositis as a focus of infection in hematological disorders: a report of 3 cases. Int J Hematol. 2003;77:171–4. Yamada K, Wasa J, Sugiura H, Horio Y. A case of multiple pyomyositis after chemotherapy for lung cancer. Gan Kagaku Ryoho. 2006;33:837–40. Keith BD, Bramwell VH. Pyomyositis after chemotherapy for breast cancer. Am J Clin Oncol. 2000;23:42–4. Singh P, Chan W, Blomfield P, McIntosh R. Pyomyositis after chemotherapy for endometrial cancer. Int J Gynecol Cancer. 2010;20:1256–8. Culine S, Kerbrat P, Kramar A, Theodore C, Chevreau C, Geoffrois L, Bui NB, Peny J, Caty A, Delva R, Biron P, Fizazi K, Bousy J, Droz JP. Refining the optimal chemotherapy regimen for good-risk metastatic nonseminomatous germ-cell tumors: a randomized trial of the Genito-Urinary Group of the French Federation of Cancer Centers (GETUG T93BP). Ann Oncol. 2007;18:917–24. Shin IB, Han W, Lee HB, Kim HK, Moon HG. Life-Threatening Hematoma in an Elderly Breast Cancer Patient Undergoing Chemotherapy. J Breast Cancer. 2023;26:514–8. Delgado Ramos GM, Piovezani Ramos G, Cotter TG. Spontaneous intramural small bowel hematoma in a patient with acute myeloid leukaemia receiving chemotherapy and nilotinib. BMJ Case Reports; 2017. Minette SE, Kimmel DW. Subdural Hematoma in Patients With Systemic Cancer. Mayo Clinic Proceedings. 64;6:637 – 42. Shimomatsuya T, Takeuchi G, Mimura K, Nakahara H, Ganeko R, Mizuno R, Hashimoto K, Himura J, Kubota Y. A Case of Spontaneous Spinal Epidural Hematoma during Chemotherapy with Paclitaxel and Ramucirumab for Advanced Gastric Cancer. Gan Kagaku ryoho. 2021;48:219–21. Eichinger S. Cancer associated thrombosis: risk factors and outcomes. Thromb Res. 2016;14:12–7. Kollmannsberger C, Tandstad T, Bedard PL, Cohn-Cedermark G, Chung PW, Jewett MA, Powles T, Warde PR, Daneshmand S, Protheroe A, Tyldesley S, Black PC, Chi K, So AI, Moor MJ, Nichols CR. Patterns of Relapse in Patients With Clinical Stage I Testicular Cancer Managed With Active Surveillance. JoJ Clin Oncol. 2015;33:51 – 7.​. Table 1 Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Cite Share Download PDF Status: Published Journal Publication published 01 Apr, 2026 Read the published version in SN Comprehensive Clinical Medicine → Version 1 posted Editorial decision: Revision requested 02 Mar, 2026 Reviews received at journal 01 Mar, 2026 Reviews received at journal 21 Feb, 2026 Reviewers agreed at journal 21 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviews received at journal 18 Feb, 2026 Reviewers agreed at journal 18 Feb, 2026 Reviewers invited by journal 17 Feb, 2026 Editor assigned by journal 17 Feb, 2026 Submission checks completed at journal 17 Feb, 2026 First submitted to journal 27 Jan, 2026 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. 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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-8714688","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":593130686,"identity":"9660ec9b-4d30-4439-a172-6dc571809fa5","order_by":0,"name":"Kaitlyn 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13:22:20","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":959271,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8714688/v1/caa9fe18fe3b87dcf642896c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"CASE REPORT: Pyomyositis in the Setting of Chemotherapy-Induced Pancytopenia: A Rare Complication of Germ Cell Tumour Treatment","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePyomyositis is a rare complication of chemotherapy whereby severe pancytopenia can lead to the formation of haematomas secondary to spontaneous bleeding from thrombocytopenia and then development of abscesses and infection due to neutropenia. It is more commonly seen in haematological malignancies [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] albeit there are case reports in multiple solid organ malignancies [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. However no research is available on case reports involving testicular germ cell tumours. It is cited in the literature that 47% of patients develop grade 3\u0026ndash;4 neutropenia, with 2% developing grade 3\u0026ndash;4 thrombocytopenia during the Etoposide and Cisplatin (EP) protocol for advanced or metastatic germ cell tumours [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. As such, given the higher rates of cytopenia with systemic treatment for germ cell tumours, it is theoretically not unsurprising that this can occur. We report the case of a 50 year old male receiving EP for metastatic germ cell who developed pyomyositis post completion of treatment.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 50 year old male presented with right sided testicular pain and swelling and was found to a have tumour on ultrasound imaging. CT imaging revealed lymphadenopathy in the para-aortic nodes and several small pulmonary nodules bilaterally. He was previously otherwise well with no significant comorbidities other than a 20 pack/year smoking history. He underwent a right orchidectomy in April 2025 with histopathology revealing two tumours: Tumour 1: 30x25x23mm mixed germ cell tumour (yolk sac 80% and seminoma 20%) and Tumour 2: 40x30x16mm mixed germ cell tumour (embryonal 80% yolk sac 10%). He was recommended for 4 cycles of etoposide and cisplatin (bleomycin withheld due to smoking history and risk of pulmonary toxicities). He completed treatment with multiple Grade 1\u0026ndash;2 toxicities including nausea, diarrhoea, insomnia and epistaxis.\u003c/p\u003e \u003cp\u003ePost Cycle 4 he developed pancytopenia, with haemoglobin (Hb) 70 g/L, white cell count (WCC) 1.9 x10\u003csup\u003e9\u003c/sup\u003e/L, neutrophil count 1.3x10\u003csup\u003e9\u003c/sup\u003e/L and platelet (PLT) count 16x10\u003csup\u003e9\u003c/sup\u003e/L which required transfusion of 2 units of packed red blood cells. He subsequently developed fevers and lower limb pain with associated right leg swelling. He presented for review 17 days post last dose of EP (C4 D20) with significant lower limb swelling, particularly of the right leg which was extremely tender to touch and he experienced severe pain in the buttocks when seated. There was concern of potential extensive deep vein thrombosis or internal bleeding secondary to thrombocytopenia causing compartment syndrome. PL was subsequently admitted to hospital for further investigation and work up.\u003c/p\u003e \u003cp\u003eCT Angiogram of the right lower limb demonstrated multiple rim-enhancing lesions in the gluteus, adductor magnus, biceps femoris and vastus medialis with subcutaneous fat stranding and oedema (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Differential diagnoses based on imaging included potential abscesses versus metastatic deposits. He was reviewed by the Orthopaedic surgical team who recommended MRI to further delineate the aetiology. MRI again demonstrated numerous rim-enhancing lesions with no internal diffusion restriction and marked muscular oedema. Findings were reported as more in keeping with metastases than abscesses. He underwent repeat staging CT Chest Abdomen and Pelvis which showed no evidence of other metastatic disease (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). His tumour markers at this time had normalised (AFP 3 bHCG\u0026thinsp;\u0026lt;\u0026thinsp;1 LDH 224). He subsequently underwent a biopsy of the right mid thigh region within the vastus intermedius muscle. Purulent fluid was aspirated and sent for culture, along with 5 core biopsies which were sent for culture and histopathology. Culture of the aspirate and tissue grew Staphylococcus Aureus. Both cytology and histopathology of the core biopsies revealed benign inflammatory tissue only with negative OCT-4 and CAM5.2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The Infectious Diseases team was consulted and they recommended oral cephalexin 1g four times a day for 2 weeks. Follow-up CT imaging performed 5 weeks after completed of antibiotics showed resolution of these collections. At the time of writing, the patient is clinically well with no evidence of relapsed mixed germ cell tumour on CT imaging.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePyomyositis remains a rare complication of chemotherapy, with a preponderance for haematological malignancies. There are twelve case reports of isolated occurrences in solid organ malignancies (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), with two of these cases representing teratoma but no clearly documented cases in mixed germ cell tumours. To our knowledge, this case report thus serves as the first documented case of pyomyositis in metastatic mixed germ cell tumour.\u003c/p\u003e \u003cp\u003eIn the context of pancytopenia secondary to chemotherapy, we know the risk of infection and the possibility of sepsis is ever present and it is something patients are counselled on extensively. Spontaneous haematomas are much less common albeit documented in a number of case reports [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], as such it needs to remain a differential in our patients who present with painful swelling in the context of thrombocytopenia. Initial instinct is often to rule out deep vein thrombosis given the pro-thrombotic nature of both cancer and chemotherapy [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The difficulty in our case was the need to rule out metastatic disease, as radiologically it was unable to be excluded. In the context of normalised tumour markers post chemotherapy and a 5-year progression free survival rate of 96% [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] \u0026ndash; the risk of metastatic disease was extremely low, however concern for seeding of the tumour with sampling of these lesions was raised by the sub-specialty teams involved. Given the unlikelihood of metastatic disease in the context of normal tumour markers and an otherwise normal restaging CT, a decision was made to proceed with radiologically guided biopsy and cytology. This confirmed Staph. Aureus pyomyositis in the right thigh, with no evidence of metastatic disease.\u003c/p\u003e "},{"header":"Conclusion","content":"\u003cp\u003eSystemic treatment for malignancies come with a vast array of side effects and toxicities. We extensively counsel patients on a number of these including the risk of infection. This case highlights that spontaneous haematomas and pyomyositis can be a complication of chemotherapy regimens that result in significant pancytopenia and thus need to remain a differential in patients who present with pain and swelling.\u003c/p\u003e"},{"header":"Declarations","content":"\u003col\u003e\n \u003cli\u003eFunding \u0026ndash; not applicable\u003c/li\u003e\n \u003cli\u003eConflicts of interest \u0026ndash; not applicable\u003c/li\u003e\n \u003cli\u003eEthics approval \u0026ndash; not applicable\u003c/li\u003e\n \u003cli\u003eConsent to participate \u0026ndash; patient provided written consent\u003c/li\u003e\n \u003cli\u003eWritten consent for publication \u0026ndash; patient provided\u003c/li\u003e\n \u003cli\u003eAvailability of data and material \u0026ndash; not applicable\u003c/li\u003e\n \u003cli\u003eCode availability \u0026ndash; not applicable\u003c/li\u003e\n \u003cli\u003eAuthors contributions \u0026ndash; Kaitlyn Trompert-Thompson was the primary author of the manuscript with assistance from Amy Smith. Amy Smith prepared figures 1 and 2. Eugene Ang prepared table 1. Tyrone Soto and Timothy Wade prepared figure 3. Amanda Stevanovic was the primary supervisor. All authors reviewed manuscript prior to submission.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHayashi T, Nozaki M, Nonaka Y, Ohashi K, Sakamaki H, Nomura T. Pyomyositis as a focus of infection in hematological disorders: a report of 3 cases. Int J Hematol. 2003;77:171\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamada K, Wasa J, Sugiura H, Horio Y. A case of multiple pyomyositis after chemotherapy for lung cancer. Gan Kagaku Ryoho. 2006;33:837\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeith BD, Bramwell VH. Pyomyositis after chemotherapy for breast cancer. Am J Clin Oncol. 2000;23:42\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh P, Chan W, Blomfield P, McIntosh R. Pyomyositis after chemotherapy for endometrial cancer. Int J Gynecol Cancer. 2010;20:1256\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCuline S, Kerbrat P, Kramar A, Theodore C, Chevreau C, Geoffrois L, Bui NB, Peny J, Caty A, Delva R, Biron P, Fizazi K, Bousy J, Droz JP. Refining the optimal chemotherapy regimen for good-risk metastatic nonseminomatous germ-cell tumors: a randomized trial of the Genito-Urinary Group of the French Federation of Cancer Centers (GETUG T93BP). Ann Oncol. 2007;18:917\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShin IB, Han W, Lee HB, Kim HK, Moon HG. Life-Threatening Hematoma in an Elderly Breast Cancer Patient Undergoing Chemotherapy. J Breast Cancer. 2023;26:514\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDelgado Ramos GM, Piovezani Ramos G, Cotter TG. Spontaneous intramural small bowel hematoma in a patient with acute myeloid leukaemia receiving chemotherapy and nilotinib. BMJ Case Reports; 2017.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMinette SE, Kimmel DW. Subdural Hematoma in Patients With Systemic Cancer. Mayo Clinic Proceedings. 64;6:637\u0026thinsp;\u0026ndash;\u0026thinsp;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShimomatsuya T, Takeuchi G, Mimura K, Nakahara H, Ganeko R, Mizuno R, Hashimoto K, Himura J, Kubota Y. A Case of Spontaneous Spinal Epidural Hematoma during Chemotherapy with Paclitaxel and Ramucirumab for Advanced Gastric Cancer. Gan Kagaku ryoho. 2021;48:219\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEichinger S. Cancer associated thrombosis: risk factors and outcomes. Thromb Res. 2016;14:12\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKollmannsberger C, Tandstad T, Bedard PL, Cohn-Cedermark G, Chung PW, Jewett MA, Powles T, Warde PR, Daneshmand S, Protheroe A, Tyldesley S, Black PC, Chi K, So AI, Moor MJ, Nichols CR. Patterns of Relapse in Patients With Clinical Stage I Testicular Cancer Managed With Active Surveillance. JoJ Clin Oncol. 2015;33:51\u0026thinsp;\u0026ndash;\u0026thinsp;7.​.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\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":"sn-comprehensive-clinical-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sncm","sideBox":"Learn more about [SN Comprehensive Clinical Medicine](https://www.springer.com/journal/42399)","snPcode":"42399","submissionUrl":"https://submission.nature.com/new-submission/42399/3","title":"SN Comprehensive Clinical Medicine","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8714688/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8714688/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction\u003c/h2\u003e \u003cp\u003eSpontaneous pyomyositis is an uncommon but serious infectious complication that typically occurs in immunocompromised patients and is more frequently reported in association with haematological malignancies. It\u0026rsquo;s occurrence in patients with solid organ tumours receiving systemic chemotherapy is rare and to date has not been described in the setting germ cell tumours.\u003c/p\u003e\u003ch2\u003eCase Presentation\u003c/h2\u003e \u003cp\u003eWe report the case of a 50-year-old male with metastatic mixed germ cell tumour who developed pyomyositis following completion of four cycles of etoposide and cisplatin chemotherapy. Post-treatment, he developed severe pancytopenia complicated by fever, significant unilateral lower limb pain, and swelling. Initial imaging demonstrated multiple rim-enhancing intramuscular lesions, raising concern for metastatic disease versus abscess formation. Despite normalised tumour markers and no evidence of disease on restaging imaging, the radiological appearance remained equivocal. Image-guided biopsy and aspiration were therefore performed, yielding purulent material that cultured \u003cem\u003eStaphylococcus aureus\u003c/em\u003e, with histopathology confirming benign inflammatory changes and no evidence of malignancy. The patient was successfully treated with oral antibiotics, with complete radiological resolution of lesions and no evidence of tumour relapse on follow-up.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThis case represents, to our knowledge, the first reported instance of pyomyositis occurring in a patient with metastatic mixed germ cell tumour following chemotherapy. It highlights the importance of considering pyomyositis and spontaneous intramuscular haematoma as differential diagnoses in patients presenting with painful limb swelling in the setting of chemotherapy-induced pancytopenia, and underscores the diagnostic challenges in distinguishing infection from metastatic disease.\u003c/p\u003e","manuscriptTitle":"CASE REPORT: Pyomyositis in the Setting of Chemotherapy-Induced Pancytopenia: A Rare Complication of Germ Cell Tumour Treatment","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-22 12:56:37","doi":"10.21203/rs.3.rs-8714688/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-02T09:30:34+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-01T08:03:12+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-21T12:55:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"226336540374014814711979036678656270082","date":"2026-02-21T12:45:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232337513464281233580195153116981533264","date":"2026-02-20T23:32:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-18T06:46:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"184801433384694699718539181328947216441","date":"2026-02-18T06:36:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-17T15:26:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-17T10:10:44+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-17T08:59:44+00:00","index":"","fulltext":""},{"type":"submitted","content":"SN Comprehensive Clinical Medicine","date":"2026-01-27T22:40:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"sn-comprehensive-clinical-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sncm","sideBox":"Learn more about [SN Comprehensive Clinical Medicine](https://www.springer.com/journal/42399)","snPcode":"42399","submissionUrl":"https://submission.nature.com/new-submission/42399/3","title":"SN Comprehensive Clinical Medicine","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"da16c85c-40e5-4a4f-8de2-acd1291af5ed","owner":[],"postedDate":"February 22nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-07T16:02:46+00:00","versionOfRecord":{"articleIdentity":"rs-8714688","link":"https://doi.org/10.1007/s42399-026-02353-4","journal":{"identity":"sn-comprehensive-clinical-medicine","isVorOnly":false,"title":"SN Comprehensive Clinical Medicine"},"publishedOn":"2026-04-01 15:59:27","publishedOnDateReadable":"April 1st, 2026"},"versionCreatedAt":"2026-02-22 12:56:37","video":"","vorDoi":"10.1007/s42399-026-02353-4","vorDoiUrl":"https://doi.org/10.1007/s42399-026-02353-4","workflowStages":[]},"version":"v1","identity":"rs-8714688","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8714688","identity":"rs-8714688","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}