Lactoferrin and lysozyme in carcinomas of the parotid gland. A comparative immunocytochemical study with the occurrence in normal and inflamed tissue.

Lactoferrin and lysozyme, parts of the non-specific defense system, were studied in normal and diseased parotid glands, using the immunohistochemical PAP-method. 31 normal and inflamed glands were investigated. The presence of lactoferrin and lysozyme was demonstrated in the acinar cells and some duct cells. The amount of these substances was increased in obstructive parotitis. The 52 carcinomas showed a distinct distribution pattern for lactoferrin (positive cases: adenocarcinomas 5 of 8; cystadenocarcinoma: 3 of 5; adenoid cystic carcinomas 2 of 4; salivary duct carcinomas 2 of 3). Some of the carcinomas in pleomorphic adenomas were positive for lactoferrin. Squamous cell carcinomas and anaplastic carcinomas were constantly negative. All carcinomas were negative for lysozyme. These observations are discussed with respect to their physiological and pathological significance.