Distribution of S-100 protein in normal salivary gland and salivary gland tumours

ABSTRACT

Immunohistochemical studies were performed for the presence of S -100 protein in noraml and neoplastic salivary gland by the peroxidase antiperoxidase [PAP] method. Among normal salivary gland the myoepitheial cells surrounding the acini and intercalated ducts were S -100 protein positive but the epithelial cells of the intercalated ducts, acini and excretory ducts were nd to be negative. In pleomorphic adenomas, S -100 protein positive cells were observed in myxomatous and chondromatous areas, which represent cells with myoepielial thelial differentiation. In adenoid cystic carcinomas, S -100 protein positive cells could be found in trahecular areas, but not in tumour cells showing cribriform pattern. In Warthins tumour, S -100 protein positive cells were present among the epithelial element and inbetween the lymphoid tissue of the tumour. The morphologic appearance of these cells was identical to that of Langerhan's cells. The presence of these cells which have a special function of antigen presentation in immune response, indicates that delayed hypersensitivity may be the main pathogenic factor in the development of Warthin's tumour. In mucoepidermoid carcinoma, S -100 protein positive cells were found in the solid sheets of the tumour, while the squamous pearls were negative. In malignant mixed salivary gland tumour, the malignant variant was clear cell carcinoma, which was negative for S -100 protein. In conclusion, S -100 protein is a useful protein of myoepithelial cells to clarify the histogenesis and for evaluatin of the prognosis of salivary gland tumours