Histological study of the human accessory parotid gland, with particular attention to the mucous cells.

Abstract

Microanatomical study of the human accessory parotid glands was made. The materials were taken from 18 cadavers (more than 40-year-old) for dissection practice by dental students at Iwate Medical University. These accessory parotid glands were re-fixed in 10 per cent neutral buffered-formalin and embedded in paraffin in routin manners. Thin sections were stained with hematoxyline and eosin, periodic acid-Shiff and Alcian blue, and prepared for light microscopic observations to investigate the atrophy of the salivary gland parenchyma, mucous cell metaplasia and mononuclear cell infiltration. The results were as follows:

1. Microanatomical findillgs of the accessory parotid glands were basically identical to those of the parotid gland. However, the intralobular duct systems of the accessory parotid gland were poorly developed.

2. Varying degrees of atrophy of the salivary gland parenchyma were found in the same age-group, and no relationship was noted betweell the atrophy of the salivary gland parenchyma and aging.

3. Varying degrees of mucous cell metaplasia of acinar and ductal epithelial cells were found in all the accessory parotid glands examined.

4. Mucous cell metaplasia in the interlobular and excretory ducts was associated with periductal mononuclear cell infiltration, however, mucous cell metaplasia in the acini and intralobular duct showed no relationship to the inflammatory change.

5. In addition to the above microanatomical findings, the pathological significance of mucous cell metaplasia in the serous salivary glands was discussed.