Mixed epithelial and stromal tumor - A solid-cystic renal neoplasm undergoing malignant transformation: A rare case report

We present a case of 53-year-old female who came with the complaints of mass on the right side of the abdomen noticed 3 weeks back. There was no history of localized swelling or rise of temperature, no history of weight loss, or evening rise of temperature. On examination, there was a flank mass which was bimanually palpable and tender. Routine laboratory investigations were within normal limits, except for the presence of hematuria in routine urinalysis. Computed tomography scan abdomen revealed a large multiloculated solid-cystic mass lesion with septation in the right-sided kidney. Cystic renal cell carcinoma was suspected and conventional open right radical nephrectomy was done. Grossly, the tumor was solid-cystic containing blood-tinged fluid. Microscopy revealed a complex tumor with both epithelial and stromal proliferation and with the aid of immunohistochemistry a diagnosis of mixed epithelial and stromal tumor undergoing malignant transformation was concluded.