Case Studies Cytologic Features of Metanephric Adenoma of the Kidney: Case Report and Review of the Literature

Metanephric adenoma (MA), also known as renal epithelial tumor, embryonal adenoma, or nephrogenic adenoma, is a rare, cortical epithelial tumor. To our knowledge, only approximately 100 cases of this tumor have been described in the literature. This tumor generally occurs in females, and has a wide age distribution of 38 to 64 and 5 to 83, with the mean age of 48.6 years and 41 years in 2 studies done by Jones et al and Davis et al. The [female to male] ratio for occurrence of this disease is 2:1.1,2 These tumors are most often benign, although few cases with metastases have been described in the literature.3-5 The origin of these neoplasms is not entirely clear; however, they are thought to be related to the Wilms tumor (WT), which represents the most mature, hyperdifferentiated form of this entity.6 Metanephri