Cystic dysplasia of the testis associated with multicystic dysplasia of the kidney.

A child with cystic dysplasia of the testis (CDT) that presented as a solid mass by ultrasound imaging is reported. The child also had ipsilateral multicystic dysplasia of the kidney (MCDK). A search of the literature revealed that unilateral renal agenesis (URA) is commonly associated with CDT. It is possible that CDT, MCDK, and URA share a common pathogenesis. Cystic changes in the epididymis were found in the patient and might be more frequently associated with CDT than previously reported. CDT should be considered in the differential diagnosis of a solid testicular mass detected by ultrasound.