The ampulla of the ductus deferens in man: morphological and ultrastructural aspects.

In order to compare the histology of the ampulla of the ductus deferens with that of the other segments of the duct in man, the seminal vesicle and the adjacent 13-15 cm of the ductus deferens were obtained during cystectomy from 15 adult men, and were processed for light and electron microscopy. Each ductus deferens specimen was divided into 3 segments: segment A or initial segment (the most proximal to the testis) showing a smooth outer surface and, on section, a uniform lumen and absence of mucosal invaginations; segment B (1.5-4 cm) showing a smooth outer surface and, on section, small cavities in the mucosa; and segment C or ampulla (3-4 cm), which was easily recognisable because of the cerebriform pattern on its outer surface. Segment A showed the usual histological pattern reported in studies of the human ductus deferens. Segment B consisted of mucosa, muscularis mucosae, submucosa, muscular coat and adventitia. The epithelial lining formed multiple branched invaginations in the lamina propria and submucosa giving rise to glandular structures. The lumen of the duct and the glands were lined by the same cell types: (1) basal cells; (2) mitochondrion-rich cells; and (3) columnar cells with the ultrastructural features of glycoprotein-secreting cells. The latter cells could be classified into 3 subtypes suggesting different stages of development: (a) with abundant mitochondria; (b) with abundant rough endoplasmic reticulum; and (c) with abundant secretory granules. Segment C or the ampulla showed the same histology as segment B except for the presence of many diverticula in the ampulla.(ABSTRACT TRUNCATED AT 250 WORDS)