Ewing's sarcoma of the cervix, a diagnostic dilemma: a case report and review of the literature.

Introduction: Ewing's sarcoma belongs to a spectrum of neoplastic diseases known as Ewing's family of tumors. This family of tumors is usually seen in osseous sites. Ewing's sarcoma of the cervix is extremely rare, with only 18 cases reported in the English literature. The immunohistochemical profile of Ewing's sarcoma overlaps with other malignancies like small cell carcinoma. The rarity and complex pathologic picture of Ewing's sarcoma of the cervix creates the potential for misdiagnosis. Hence, we believe this case needs to be reported to add to the available literature.

Case Presentation: A 49-year-old white Caucasian woman presented with vaginal bleeding. A pelvic examination revealed a cystic lesion arising from her cervix. Examination of a biopsy specimen revealed a poorly differentiated neoplasm, with sheets of small hyperchromatic cells, staining weakly for neuroendocrine markers. She was diagnosed with small cell carcinoma and started on concurrent chemotherapy and radiation. However, additional positive immunostaining for CD99 was strongly suggestive of Ewing's sarcoma. Fluorescence in situ hybridization revealed ESWR1 gene rearrangement, confirming Ewing's sarcoma. Our patient underwent surgery, which confirmed stage IIB Ewing's sarcoma. She received adjuvant chemotherapy but died from progressive metastatic disease after four cycles.

Conclusion: With early diagnosis and appropriate treatment, Ewing's sarcoma of the cervix can be a potentially curable disease. However, owing to overlapping clinical and histopathological features, the diagnosis poses a challenge to oncologists and pathologists. This article guides pathologists to consider Ewing's sarcoma in the differential diagnosis of small cell carcinoma with weak staining for neuroendocrine markers. This literature review will benefit oncologists encountering this rare entity.