Vascular Leiomyosarcoma of the Thigh: A Rare Presentation.

High-grade mesenchymal soft tissue tumors are rare neoplastic lesions that occur uncommonly in the extremities and in other sites of the body. Herein, we report a case of high-grade vascular leiomyosarcoma of the thigh. The patient was a 72-year-old male with a 4-day history of swelling in his right thigh. Excision biopsy of the tumor showed highly pleomorphic tumor cells arranged typically in perivascular fashion with large areas of hemorrhage and necrosis. Immunohistochemistry was positive for vimentin, smooth muscle actin, and showed a 90% proliferation index on ki-67 labeling. Vascular leiomyosarcomas comprise a group of very infrequent tumors with varied presentation and can occur at unusual sites.