[Changes in area of mucous membrane in otosclerosis].

In 98 samples of middle-ear mucosa, taken from patients during otosclerotic stapes surgery, considerable pathological changes in the organization of the capillaries were found (endothelial hydrops, proliferation of the intima and adventitia, total obliteration of small vessels). They caused pathological reactions of the mesenchymal elements of the submucosa: fibrocytes undergo lysis, collagen fibres show fibolysis and hyalinosis. Free and cellular bound calcium deposits are located in these lytic areas. Even the epithelial stratum reveals uncommon inclusions such as glycogen and acid mucopolysaccharides. The basement membranes of the capillaries as well as of the epithelium show enlargements and solution of their ultrastructure. The changes of the connective tissue and of the epithelium are secondary to the capillary obstructions.