Primary High-Grade Intraperitoneal Sarcoma Mimicking a Germ Cell Tumor in an 8-Year-Old Girl in Somaliland: A Diagnostic Challenge.

Background: Primary intra-abdominal sarcomas in children are rare, aggressive malignancies that often present with non-specific clinical and radiological features. Differentiation from more common pediatric abdominal tumors, such as germ cell tumors, can be challenging, particularly in resource-limited settings with restricted access to advanced pathology and molecular diagnostics. Case Presentation: We report an 8-year-old previously healthy girl from Somaliland presenting with a 2-week history of progressive abdominal distension, weight loss, and low-grade fever. Imaging revealed a large heterogeneous abdominopelvic mass suggestive of a germ cell tumor. Due to limited access to biopsy, empiric germ cell tumor-directed chemotherapy was initiated; however, no clinical or radiological response was observed after two cycles. Exploratory laparotomy identified a large intra-peritoneal mass with omental and nodal involvement, and cytoreductive surgery was performed. Histopathology showed a high-grade malignant neoplasm with pleomorphic round-to-spindle cells and rhabdoid features. Immunohistochemistry demonstrated diffuse desmin positivity and negative myogenin expression; INI1 testing was unavailable, resulting in a diagnosis of primary high-grade intra-peritoneal sarcoma. Despite postoperative chemotherapy, the disease progressed, and the patient died approximately 3 months after treatment. Conclusion: Early histopathological confirmation is essential in atypical pediatric abdominal masses. Reliance on imaging alone may lead to misdiagnosis and delayed treatment. Limited diagnostic resources remain a major barrier to optimal care in low-resource settings.