Renal Vein Leiomyosarcoma

**Semantic type:** Neoplastic Process

**Definition:** An aggressive malignant smooth muscle neoplasm, arising from the renal vein. It is characterized by a proliferation of neoplastic spindle cells.

**Synonyms:** - Leiomyosarcoma of Renal Vein - Leiomyosarcoma of the Renal Vein