Renal angiomyoadenomatous tumor.

We report a case of a 40-year-old woman with renal angiomyoadenomatous tumor, a rare neoplasm with only 6 previous cases reported in the literature. Unlike our case, most tumors have been identified in middle-aged males; they present as well-circumscribed, encapsulated tan-brown masses with variably prominent cystic areas. Microscopically, the tumors have a variably thick leiomyomatous capsule, which invaginates into the tumor and intermixes with tubules or solid nests of clear epithelial cells. The epithelial cells have low-grade basally oriented nuclei, and their basement membranes are intimately linked to a labyrinthine network of capillaries and pericytes. Microscopically, these tumors can be confused with clear cell carcinoma, papillary carcinoma, mixed epithelial and stromal tumors, and angiomyolipoma. This is also the first case report correlating the radiographic and morphological findings of this rare entity. The differentiating features of these neoplasms and a review of literature of are herein presented.