Clinical pathology of cystic nephroma: An analysis of 20 cases

Objective To study the clinical features, pathological morphology, immune phenotypes and differential diagnosis of cystic nephroma. Methods Twenty cystic nephroma patients admitted to our hospital from 2006 to 2013 were included in this study. The clinical features, pathological morphology, immune phenotype and differential diagnosis of cystic nephroma were analyzed. Results The incidence of cystic nephroma was higher in male patients than in female patients with an average age of 52 years. Their clinical symptoms were usually found in physical examination. B-type ultrasound, CT and MRI showed that cystic nephroma was an occupying lesion in kidney with left kidney involved. The tumor was frequently located in the lower pole with a maximum average diameter of 3.0 cm and usually surgically removed. Of the 20 cystic nephroma patients, 7 underwent radical nephrectomy, 6 underwent partial nephrectomy, 5 received enuleation with nephron preserved, and 2 received decompression. Flat, cubic or hobnail epithelial cells were found in the cystic lining under microscope. Fibrous tissue was observed in the tumor septum. Immunohistochemistry staining showed CK(7/7), CK7(2/3), CK19(1/1), CD10(1/7), and PR(3/3), ER(2/3), CD10(1/7). Conclusion Cystic nephroma is a rare and benign cystic tumor in kidney with no specifc clinical manifestations. B-type ultrasound, CT and MRI are the most commonly used accessory tools for its diagnosis. Pathology is the gold standard for its diagnosis. Cystic nephroma should be differentially diagnosed from partially differentiated cystic nephroblastoma and cystic renal cell carcinoma. Cystic nephroma is usually surgically removed.