title: Malignant external otitis: early histopathologic changes and pathogenic mechanism.
abstract: The histopathologic changes during the early stage of malignant external otitis (MEO) were studied in two patients, one a non-diabetic. The specimens were obtained by an en bloc excision of the diseased tissue of the external ear canal through a retroauricular approach. The most prominent histologic features of the early stage of MEO consist of a thick layer of almost acellular, partly degenerated, collagen extending from the cartilage into the dermis, which most likely existed prior to the penetration of the microorganism. This finding supports our concept that MEO is a disease which develops as a results of invasion of opportunistic organisms into tissue previously devitalized, probably due to vascular compromise and that these latter features constitute the basic mechanism of the entire disease process.
mesh_terms: D000368:Aged; D002356:Cartilage / Q000473:pathology; D003094:Collagen; D003238:Connective Tissue / Q000098:blood supply / Q000473:pathology; D004424:Ear Canal / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D008297:Male; D010032:Otitis Externa / Q000209:etiology / Q000382:microbiology / Q000473:pathology*; D013997:Time Factors
chemical_list: D003094:Collagen