Middle Ear Cholesteatoma in a Postmortem Temporal Bone: A Case Highlighting Variation in Regional Inflammation.

Cholesteatoma is an abnormal accumulation of keratinizing squamous epithelium within the middle ear that can behave in a locally destructive manner and erode the ossicular chain. Chronic inflammation and Eustachian tube dysfunction is thought to drive this process. We present a temporal bone specimen from a 38-year-old woman with a lifelong history of right-sided otorrhea and conductive hearing loss, who died of hypoxic-ischemic brain injury after cardiac arrest. Histologic examination revealed a cholesteatoma eroding the incus, with marked regional variation in perimatrix inflammation ranging from mild fibrosis to dense inflammatory infiltration with neovascularization. Notably, areas of more severe inflammation corresponded to a thicker, hyperplastic epithelial matrix, illustrating within a single specimen the spatial link between the inflammatory microenvironment and epithelial proliferation proposed to underlie cholesteatoma progression and local tissue destruction.