Gland formation in otitis media. An ultrastructural study in humans

In an effort to evaluate mechanisms of new gland formation in otitis media, 14 human middle ear mucoperiostial tissue samples were obtained from 7 patients with a history of this disease. In areas of inflammatory reaction, especially in the promontory and anterior wall, the mucoperiosteum acquires polyploidal characteristics, with occasional epithelial breaks. The epithelium becomes thicker and the cells develop increased secretory activity. The invaginated portion of these polyploidal formations can be observed as pits lined by secretory epithelium. The cells in these invaginated areas: (i) fuse in areas of epithelial ruptures, leaving spaces into which cells secrete; (ii) develop dense cellular nests that bud off the epithelium, leaving empty spaces into which cells secrete. It is proposed that new gland formation can occur by means of fusion and formation of cellular nests that bud off the epithelium.