[Papillary cystadenoma of the epididymis: a report of 2 cases and review of the literature].

To study the clinicopathological characteristics of papillary cystadenoma of the epididymis.Using routine pathology and immunohistochemistry, we observed the surgically obtained samples from 2 cases of papillary cystadenoma of the epididymis, analyzed their pathological features and clinical presentations, and reviewed the related literature.The 2 patients were both adult males. The tumors typically manifested as painless swelling in the epididymis, with occasionally dull pain and tenesmus in 1 of the cases. Pathologically, the lesions exhibited three morphological features, i. e., dilated ducts and small cysts surrounded by fibrous connective tissue, adenoid papillary hyperplasia into the cysts embraced by fibrovascular stroma, and acidophil substance present in the cysts. Immunohistochemistry showed that the tumors were strongly positive for CK8/18, CK7, and EMA, but negative for CK20, CEA, MC, Calretenin, P53, P63, SMA, VHL, and CD10, with the positive rate of Ki-67 <1%. Follow-up visits revealed good prognosis in both cases.Papillary cystadenoma of the epididymis is a rare benign tumor in the male urogenital system, which may be accompanied by the VHL syndrome. Surgery is the first choice for its treatment.