Anatomical relationships between testis and epididymis during the fetal period in humans (10-36 weeks postconception)

Objective: To determine the anatomy of the epididymis and its relationship with the testis during the fetal period in normal individuals. Methods: We studied bilaterally 146 testes and epididymides taken from 73 normal fresh human fetuses ranging in age from 10 to 36 weeks postconception. The epididymal anatomy was classified in six types: type I: the epididymis is connected to the testis by its head and tail and the epididymal body is separated from the testis; type II: the epididymis is completely attached to the testis; type III: the epididymis is attached to the testis only by its head; type IV: the epididymis is attached to the testis only by its tail; type V: the epididymis is completely detached from the testis; type VI: segmental atresia of the epididymis. Results: Normal epididymal anatomy, considered type I and type II, was found in 89.72% and in 7.53% of the cases, respectively. Type III and type IV epididymal anatomy was found in only 2.05% and 0.68% of the cases, respectively. We did not find types V and VI epididymal abnormalities. Conclusions: Our results show that irrespective of testicular position during the fetal period, the incidence of epididymal abnormalities in normal fetuses is very low (2.75%) when compared with previous reports in patiens with cryptorchidism and/or with a patent processus vaginalis (36-79%).