Cystic dysplasia of the testis (CDT) is a rare congenital defect chara
cterized by the formation of multiple irregular cystic spaces in the m
ediastinum testis. Go-existent genitourinary lesions have commonly bee
n associated with this lesion and have included absence of the ipsilat
eral kidney, duplication anomalies, and cryptorchidism. We describe th
e first case in which multicystic dysplastic kidney (MCDK) is associat
ed with CDT.