Normal epididymal anatomy in boys

It is accepted that a range of epididymal anomalies exists in boys with 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 epididymal 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 was recorded for all exposed testes. Indications for surgery included hydrocele or hernia in 85 boys, torsion in 8 and varicocele in 1. A total of 112 epididymides was examined and the configurations were recorded 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 attachment only in 0 (0%), type 5-nonfusion in 1 (0.9%) and type 6-anomalies of ductal patency in 0 (0%). These data reveal that the most common epididymal configuration in normal boys is a looped epididymis with the head and tail attached (84%) followed by complete fusion with the testes (12.5%). Other variations are rare. Absence of the epididymis was not observed.