Vol. 7, Issue 1, Part A (2025)

Background: The non-sclerosing epithelioid variant of fibrosarcoma is an extremely rare soft tissue tumor characterized by epithelioid morphology with minimal stromal sclerosis. It poses significant diagnostic challenges due to its histologic overlap with other epithelioid malignancies, such as epithelioid sarcoma, carcinoma, and synovial sarcoma.

Case Presentation: We report the case of a 28-year-old male with a painless, enlarging nodule on the left forearm. Imaging revealed a well-circumscribed soft tissue mass. Histopathological examination demonstrated sheets of epithelioid cells with minimal stroma. Immunohistochemistry revealed positivity for vimentin and CD99, with negativity for PanCk, S100, CD34, and desmin. The findings confirmed the diagnosis of the non-sclerosing epithelioid variant of fibrosarcoma. The patient underwent surgical excision with negative margins. After a 12-month follow-up, the patient was free of recurrence or metastasis.

Conclusion: This case highlights the importance of recognizing this rare variant of fibrosarcoma to avoid misdiagnosis and inappropriate management. Awareness and comprehensive immunohistochemical analysis are critical for accurate diagnosis.