Immunoreactive vasoactive intestinal polypeptide in acinic cell carcinoma of the parotid gland

Vasoactive intestinal polypeptide (VIP) in the neoplastic cells of acinic cell carcinomas arising in the human parotid gland was found immunohistochemically, whereas other parotid gland tumors, such as pleomorphic adenoma, Warthin's tumor, oxyphilic adenoma, mucoepidermoid carcinoma, adenocarcinoma, and adenoid cystic carcinoma, did not show positive immunoreactivity for VIP. The acinic cell carcinoma stained with Grimelius impregnation and had dense core granules immunoreactive with anti-VIP serum. Moreover, a comparatively high concentration of immunoreactive VIP was detected by radioimmunoassay in an acinic cell carcinoma, whereas VIP concentration of the other tumors was undetectable.