Unusual sonographic appearance of an epidermoid cyst of the testis.

Epidermoid cyst of the testis is a rare benign testicular tumor with varied sonographic appearances. We present a case in which two specific ultrasonographic patterns were seen: (1) an "onion ring" configuration of alternating hyperechoic and hypoechoic regions, described previously as being characteristic of this lesion, and (2) a heterogeneous region with multiple punctate hyperechoic foci.