Myofibroblasts in chronic otitis media.

Cells which may be tentatively described as myofibroblasts have been identified by transmission electron microscopy from samples of inflammatory tissue present in the tympanic cavity of ears demonstrating clinical chronic otitis media. These cells possess the ultrastructural characteristics of a markedly indented nucleus, well organized bundles of cytoplasmic microfilaments, and plasmalemma specializations resembling desmosomes. Myofibroblasts are contractile cells which are present in a number of pathological conditions characterized by tissue contraction or distortion such as hepatic cirrhosis, Dupuytren's contracture, and hypertrophic scars. It is possible to hypothesize that myofibroblasts in chronic otitis media may exert synchronized contractile forces which distort the tympanic membrane or ossicular chain and thus lead to conductive hearing loss.