Enterogenous Cyst of the Testis

ABSTRACT

We present a rare case of an enterogenous cyst of the testis in a 21-year-old man. On ultrasonography, an ovoid hypoechoic solid mass (2x2x1.5 cm) was confined to the right testis. The left testis and bilateral epididymis were within normal limits. Grossly, the tumor was a unilocular cystic mass, without a solid component. Microscopically, the cystic mass was composed of mucin-secreting simple columnar epithelial lining cells, lamina propria and a well-differentiated muscularis propria. There was no evidence of any germ cell derivatives or neoplasia in the cystic mass and in the surrounding testicular parenchyma. Immunohistochemistry showed a positive reaction for cytokeratin and the epithelial membrane antigen in the epithelial lining; in addition, it was positive for smooth muscle actin in the well-differentiated muscularis propria.