Metanephric adenoma: A report of two cases and review of the literature.

Metanephric adenoma (MA) is a rare benign renal neoplasm of originating in the epithelial cells, which is often difficult to distinguish from malignant neoplasms preoperatively. In this study we present two cases of patients with MA with the aim to analyze the clinical manifestations, imaging, pathology, diagnosis and treatment of MA. Computed tomography (CT) of the first case revealed a solid well-demarcated tumor, 5.5 × 5.4 cm in diameter. Ultrasound examination of the second patient revealed a hypoechoic mass with solid aspect and irregular limits in the upper pole of the right kidney. CT confirmed the presence of a 4 cm expansive tumoral formation with intermediate attenuation and minimum venous contrast enhancement at that anatomic site. The two cases underwent surgery and the patients were free from recurrence after a follow-up period of 18 months to 2 years. We also present a supplementary review of previously published cases and related literature.