[Intraepithelial mast cells in the vocal cords and nasal mucosa]

Leukocytes and mast cells have been described in the human nasal mucosa and epithelium of the lower airways (Bonneville 1988, Goodman and Lefrancois 1989, Guy-Grand 1991, Denburg 1992). In mast cells, heterogeneity of mucosal and connective tissue mast cells has been observed. In the present electron microscopic study, the epithelium of the upper airways (larynx and nose) of patients, suffering from chronic laryngitis, was examined with special regard to intraepithelial mast cells. Numerous mast cells were found in the stratum spinosum of the true vocal cords showing extensive elongated surface folds that had little contact to epithelial cells. Desmosomes were absent. Mucosal mast cells are characterised by four types of membrane-bounded granules, whereas serosal mast cells only showed two different types of granules and resembled blood basophiles. Migration of connective tissue mast cells into the epithelium could not be observed. According to our findings, mucosal and serosal mast cells belong to different cell lines.