Low-grade fibromyxoid sarcoma of the renal pelvis: first report.

Sarcomas of the genitourinary tract are quite rare, accounting for 2.1% of all soft tissue sarcomas and have a poor prognosis. Kidney sarcomas are quite rare, representing 1-3% of malignant renal cases. Low-grade fibromyxoid sarcoma (LGFS) of the kidney is an exceedingly uncommon, indolent but metastasizing soft tissue sarcoma with deceptively benign-appearing histological features. The estimated 5-year overall survival seems to be over 90%, but very late local relapses and distant metastasis may occur, which underlines the need for a long-term follow-up. We present a case of a 48-year-old male patient with a LGFS located on the renal pelvis. This is probably the first report of LGFS arising from the renal pelvis.