Abstract
Painless solid testicular masses on ultrasonography are commonly malignant. However, if the lesion is well demarcated, rounded, and hypoechoic with alternating hyperechoic and hypoechoic layers, and no internal vascular flow, the possibility of an epidermoid cyst should be considered. Epidermoid cysts are uncommon benign testicular lesions and are extremely rare in the intrascrotal extratesticular region. Including these cysts in the differential diagnosis may allow the urologist to perform testis-sparing surgery. Teaching Point: The possibility of an epidermoid cyst should be considered when a scrotal mass shows an 'onion ring' appearance on sonography and no vascularity on Doppler.