Immunoreactive somatostatin in Warthin's tumor.

The presence of somatostatin (SRIF) in the neoplastic epithelial cells of certain Warthin's tumors arising in the human parotid gland was found immunohistochemically, whereas the other parotid gland tumors, such as pleomorphic adenoma, oxyphilic adenoma, mucoepidermoid tumor, adenocarcinoma, and adenoid cystic carcinoma, did not show positive immunoreactivity for SRIF. The SRIF-positive Warthin's tumor had dense core granules immunoreactive with anti-SRIF serum. Moreover, a comparatively high concentration of immunoreactive SRIF was detected by radioimmunoassay in an SRIF-positive Warthin's tumor, although the other tumors also contained low levels of immunoreactive SRIF.