Multinucleate epithelial cells in the ductuli efferentes of human epididymis

The histological and ultrastructural study of the ductuli efferentes in epididymides from 40 adult men revealed the occurrence of multinucleate epithelial cells in all specimens. These cells appeared in the luminal protrusions of epithelial folds and correspond to either principal or ciliated cells. The ultrastructure of their cytoplasm did not differ from that of their respective mononucleate cells. Multinucleate cells contained 3-20 closely juxtaposed nuclei, thus appearing much more irregularly outlined than those of the mononucleate epithelial cells. Multinucleation four times more frequent in the principal cells than in the ciliated cells. The number of multinucleate cells increased progressively from the age of 60 years onwards. The average number of nuclei per cell increased in the fourth decade of life, was maintained up to the eighth decade, and then increased again.