Primary sclerosing epithelioid fibrosarcoma of the kidney: A rare case report

Sclerosing epithelioid fibrosarcoma (SEF) represents a rare variant of fibrosarcoma primarily arising in the deep soft tissue of the extremities and trunk. The author reported a rare case of SEF emerged primarily in the kidney. Clinically, the patient complained of hematuria. The diagnosis was confirmed by histological examination and immunohistochemical staining of MUC4. Subsequent fluorescence in situ hybridization (FISH) analysis detected the presence of EWSR1 gene rearrangement, further confirming the histological diagnosis. The patient has been alive with 12 months follow-ups after nephrectomy. The disease should be considered in the differential diagnosis for primary renal tumors.