Peritoneal seeding following incomplete resection of mixed epithelial stromal tumor of the kidney: First case report.

Mixed epithelial stromal tumor (MEST) is rare and typically benign renal cystic neoplasm that cannot be clinically distinguished from cystic renal cell carcinoma. Its mainstay course of diagnosis and treatment remains surgical excision. Recurrence and malignant transformation is rare but has previously been described.