Mixed epithelial and stromal tumor of the kidney (MEST).

OBJECTIVE To report an unusual case of renal tumor and review the literature. METHODS We present a 20 years old female with a history of acute right pyelonephritis. The ultrasound study revealed a tumor-like image in the lower pole of the right kidney . The CT-scan showed a mixed solid and cystic mass of 7 cm. in the lower pole of the right kidney. RESULTS A right laparoscopic partial nephrectomy was performed. The total operative time was 90 minutes, with 24 minutes of warm ischemia. The estimated blood loss was 50 ml. and the length of stay (LOS) 36 hours. The pathology findings confirm a mixed epithelial and stromal tumor (MEST) of the kidney. CONCLUSION Mixed epithelial and stromal tumor (MEST) of the kidney is a benign and rare condition that doesn't show a clear difference with other renal tumors in image studies. Nephron-sparing surgery with margin study is the standard treatment when is feasible.