The submucous layer of the middle ear in chronic otitis media. I. Secretory otitis media. A histological and ultrastructural study.

Abstract

In continuation of a previous paper on the middle-ear epithelium in chronic Secretory and suppurative otitis, the authors describe the conditions of the submucosa in the same diseases. First, the stroma and the cellular population in the submucosa of the normal middle ear are described, in particular the pericyte and its presumed potential properties as the precursor of histiocytes as well as fibroblasts. Moreover, the authors mention the evidence indicating that the formation of collagen fibrils takes place in an intracellular site, in relation to the endoplasmatic reticulum. The most important cellular changes in the submucosa in chronic Secretory otitis are a material increase in the number of fibrocytes, fibroblasts, and histiocytes as well as some increase in the number of neutrophilic leukocytes and mast cells. On the other hand, eosinophils were not present. This militates against allergy being the cause of Secretory otitis. Finally, a proliferation of the capillary network was found, with an increased number of pericytes and histiocyte-like cells in relation to the pericytes. In the stroma there was an increased number of collagen fibrils, without signs of degenerative changes. The studies showed no essential morphological differences between otitis with serous and otitis with mucous secretion. The quantitative and qualitative differences in the secretion must be explained on the basis of the previously demonstrated epithelial changes in these disease conditions.