Clinical and ultracytochemical investigation of sialadenosis.

OBJECTIVE: The records of 65 patients with sialadenosis treated between 1989 and 2002 at Tokyo Women's Medical University Hospital were studied clinically and ultracytochemically, focusing on the secretory granules of the acinar cells.

MATERIAL AND METHODS: Biopsies of parotid glands were performed in 18 patients. The obtained parotid tissues were investigated electron microscopically and ultracytochemically. For the ultracytochemistry of carbohydrates, the periodic acid-methenamine silver method (PAM) and lectin-gold technology were used. An immunohistochemical study using anti-alpha-amylase antibody was also undertaken.

RESULTS: Light microscopically, the acinar cells of the parotid glands of sialadenosis patients were pale and swollen. Ultrastructurally, most secretory granules of the acinar cells were homogeneous and could be classified into two types: electron-lucent and electron-dense. The former type was seen mainly in patients with anorexia nervosa and bulimia, while the latter type was predominantly found in patients with hypertension or diabetes mellitus. Both types of granule reacted uniformly with PAM. Acinar cells from normal parotid glands contained spherical dense cores which showed little reaction. The peripheral rims of the granules were strongly stained. Lectin-gold binding in the granules showed a similar pattern to PAM staining. Immunohistochemically, the acinar cells of the sialadenosis patients reacted with anti-alpha-amylase antibody. The dark granular type showed more intense reaction than the light granular type.

CONCLUSION: These findings suggest that amylase and glycoconjugates are present in the secretory granules in sialadenosis although the granule structure is abnormal, being enlarged by disturbance of normal protein synthesis and release at the cellular level and by dense-core formation in the granules.