Existence and distribution of melanocytes and HMB-45-positive cells in the human minor salivary glands.

The existence and distribution of melanocytes in the human minor salivary glands were investigated in a series of autopsy and biopsy materials. The cells with the following characteristics were regarded as melanocytes; spindle-shaped or dendritic cells with fine granular pigments: (i) stained brownish-black by hematoxylin-eosin stain, and black by Masson-Fontana's silver impregnation method; and (ii) disappeared after treatment with peroxide and potassium permanganate solution. In addition, the expression of antigen identified by anti-HMB-45 antibody in serial sections with melanocytes was examined. Melanocytes were found in eight (1.8%) of 445 cases, and there was no relationship between the existence of melanocytes and significant diseases of the subjects. Various numbers of melanocytes were distributed in fibrous tissue around the interlobular ducts, intralobular ducts and acini, but were not in direct contact with the epithelia. Neither melanocytes nor melanin granules were found in the salivary gland epithelia. HMB-45-positive cells without intracytoplasmic fine granules were found solitarily or in small groups in periductal and periacinar fibrous tissues with or without slight infiltration of small mononuclear cells.