Papillary Cystadenofibroma of the Epididymis: A Case Report.

To date, only 1 example of cystadenofibroma of the epididymis has been reported in the English literature. Here, we present a second cystadenofibroma originating from the epididymis of a 54-year-old man who presented with painful swelling in the scrotum. The scrotal mass measured 6.3 cm and contained a clear yellow, serous to gelatinous fluid-filled cyst with internal papillae. Microscopically, the mass contained both stromal and epithelial components. The stromal component consisted of spindle cells arranged in small intervening fascicles, forming simple cyst and papillae. The cyst and papillae were lined by cuboidal to columnar and ciliated epithelium. Immunohistochemistry staining showed that the stromal component was positive for estrogen receptor, progesterone receptor, and CD10, which are characteristic of ovarian-type stroma. However, the epithelium lining was positive for keratin cocktail AE1/3&CAM5.2, CD10, PAX8, androgen receptor, and alpha-1 antitrypsin, suggesting a possible Wolffian duct origin.