It is accepted that a range of epididymal anomalies exists in boys wit
h cryptorchidism, varying from ductal patency aberrations to abnormal
attachments of the epididymis to the testes or even complete absence.
Despite several series characterizing these variations, there are few
studies of normal controls for comparison. We document normal epididym
al anatomy in boys. During an 18-month period ending in 1991, 94 boys
(mean age 4.8 years, range 1 month to 18 years) underwent inguinal or
scrotal exploration unrelated to cryptorchidism. Epididymal anatomy wa
s recorded for all exposed testes. Indications for surgery included hy
drocele or hernia in 85 boys, torsion in 8 and varicocele in 1. A tota
l of 112 epididymides was examined and the configurations were recorde
d as type 1 - head and tail attachment with a ''looped'' body in 94 of
112 cases (83.9%), type 2 - complete attachment to the testis in 14 (
12.5%), type 3 - head attachment only in 3 (2.7%), type 4 - tail attac
hment only in 0 (0%), type 5 - nonfusion in 1 (0.9%) and type 6 - anom
alies of ductal patency in 0 (0%). These data reveal that the most com
mon epididymal configuration in normal boys is a looped epididymis wit
h the head and tail attached (84%) followed by complete fusion with th
e testes (12.5%). Other variations are rare. Absence of the epididymis
was not observed.