Melanocyte system of the endolymphatic duct and sac.

One hundred fourteen human temporal bones from 64 individuals were studied for the presence of melanized melanocytes about the endolymphatic duct and sac. Specimens were from Caucasians (104), Orientals (6) and Negroes (4). Of the specimens from people above nine years of age 79% demonstrated melanized melanocytes about the endolymphatic duct and sac, as well as occasionally about blood vessels in the adjacent bone. These represented 74% of the Caucasian and 75% of the Negro and Oriental individuals. Pigment granules were noted in occasional epithelial lining cells and in macrophage-type cells within the lumen. Heavily melanized melanocytes were noted in five of six specimens of Ménière's disease (all from Caucasian individuals), five of five specimens with previous labyrinthitis (two of which were from a Negro woman), and in occasional specimens from patients with presbycusis, metastatic carcinoma (three of the four adult Oriental patients), chronic otitis media, otosclerosis and lymphoma, as well as in several apparently normal specimens. No clear cut correlation of degree of melanization with specific disease processes can be discerned.