[Clinical analysis of 8 cases of the mixed epithelial and stromal tumour family of kidney].

Objective: To investigate the diagnosis and treatment of the mixed epithelial and stromal tumour family of kidney. Methods: Eight cases of the mixed epithelial and stromal tumour family of kidney were retrospectively analyzed. Before operation, radiologic evaluation was performed in all cases, including CT and MRI scan. Three cases were diagnosed as cystic renal cell carcinoma, 5 cases were diagnosed as renal complex cysts. Radical nephrectomy was performed in 4 cases and partial nephrectomy was performed in 4 cases. Results: The manifestation of the pathological specimens were multilocular cystic or cystic solid tumors grossly. Microscopically, the tumors were composed of two components, epithelial and stromal. Immunohistochemical staining showed that the epithelial components of the tumors were positive for AE1/AE3 (8/8), CK18 (3/3), and CK-7 (1/1). The stromal components were positive for PR (8/8), ER (6/8), Vim (6/6), Desmin (5/5), and SMA (5/5). HB-45 staining were negative (7/7) and Ki-67 staining were negative (7/8). All cases were diagnosed as the mixed epithelial and stromal tumour family of kidney. All patients were followed up for 3-124 months, with a median follow-up of 41 months. No tumour recurrence or metastasis were observed. Conclusion: The mixed epithelial and stromal tumour family of kidney mostly occurs in women, but have no specific clinical manifestations. They were often misdiagnosed as cystic renal cell carcinoma before operation. These following imaging features may be helpful for diagnosis. The definite diagnosis of the disease depends on the pathological examination, and immunohistochemistry plays an important role in differential diagnosis. Surgical treatment is the first choice, and partial nephrectomy is feasible. Most of the tumors are benign, and the patients can be cured after complete excision.