Superficial Ewing Sarcoma of the Rectum: A Case Report and the Utility of Molecular Diagnostics.
Jessica L Muldoon, Laura M Warmke, Ahmed K Alomari et al.
✦ AI-curated · Sources linked
Case in brief
A 38-year-old male presented with rectal bleeding and was found to have an ulcerated polyp near the dentate line. An excisional biopsy revealed a monotonous round cell malignancy with necrosis and high mitotic activity. Immunohistochemical studies were positive for CD99 and NKX2.2, and next-generation sequencing confirmed an EWSR1::FLI fusion, diagnosing superficial Ewing sarcoma. Imaging showed no metastasis, and re-excision revealed no residual tumor.
What made this case unusual
This case is notable as it represents only the second molecularly confirmed instance of superficial Ewing sarcoma originating from the rectum.
Diagnostic / clinical pearl
Clinicians should consider Ewing sarcoma in the differential diagnosis of rectal tumors, especially in younger patients presenting with unusual lesions.
Why it matters
The case highlights the importance of molecular diagnostics in confirming rare presentations of Ewing sarcoma, which can aid in accurate diagnosis and management.