Bilateral epidermoid cysts of the testis: sonographic and MRI findings.

Epidermoid cysts of the testis are rare benign lesions, without malignant potential, that can be managed conservatively with cyst enucleation and testis-sparing surgery. Bilateral epidermoid cysts in the testes have been reported very infrequently. We report the sonographic and MRI findings in a patient who presented with a palpable nodule in only 1 testis, but in whom sonography showed bilateral lesions. On sonography, the cysts had an internal "onion-ring" structure; color Doppler signals were absent. On MRI, the cysts had a laminated appearance, with alternating low- and high-signal-intensity areas on T2-weighted images. These imaging findings and the negative results of laboratory tests for tumor markers suggested the correct diagnosis, and testis-sparing surgery could be performed.