Cytoplasmic expression of p53 protein and its morphological features in salivary gland lesions

An immunohistochemical study of p53 protein was carried out on 45 salivary gland lesions using a monoclonal antibody, Bp53-12, raised to the intracellular domain of the p53 protein. p53 protein expression was found in 34.4% of 32 salivary gland carcinomas. Nuclear p53 expression was detected in tumor cells but not in non-neoplastic cells, except in one salivary duct carcinoma. The perinuclear cytoplasm of luminal duct cells was specifically positive for the antibody used here. Cytoplasmic p53 expression was observed mostly in non-neoplastic cells. There was a tendency for the cytoplasmic staining of p53 protein to be observed in the normal cells adjacent to p53-positive carcinomas, but none of the normal cells were positive in the tissues surrounding p53-negative carcinomas. Cytoplasmic expression of p53 protein in salivary gland tissues seems to be correlated with tumorigenesis.