Clinical-radiologic correlation of mixed epithelial and stromal tumor of the kidneys: Cases analysis

BackgroundMixed epithelial and stromal tumor of the kidney (MESTK) is a rare tumor, with few malignant cases reported. Occurring mostly in middle-aged women, it is characterized by a biphasic pathological structure.MethodsThis study retrospectively reviewed the imaging findings and medical records of six MESTK cases of a single institution in a 10-year period.ResultsAll of the patients were middle-aged women without hormone therapy history. The typical image was a renal tumor with varied cystic components. Half of the cases had sinus invagination, but only one had intratumor calcification. On imaging studies, four were Bosniak Category IV, one was Category III, and one presented as a solid tumor. The mean RENAL nephrometry score was 9.3. Five patients underwent partial nephrectomy, with no statistical renal functional deterioration after nephron-sparing surgery. There were no peri-operative complications.ConclusionSurgery remains the treatment of choice for MESTK, and nephron-sparing surgery should be considered in feasible cases.