Primary squamous cell carcinoma of the middle ear invading the cochlea. A histopathological case report.

This report describes the histopathological changes in the temporal bone of a 71-year-old man who died of meningitis and epidural abscess complicated by primary squamous cell carcinoma of the middle ear. The present case is unusual and differs somewhat from previously reported cases of the primary squamous cell carcinoma of the middle ear in three respects: 1) an extensive invasion of the cancer into the membranous labyrinth, 2) cholesterol deposits in the cochlear spiral canal, and 3) presence of ossifying labyrinthitis. Among these findings, extensive involvement of the inner ear by cancer destroying the lower part of the otic capsule is particularly unusual. It is assumed that squamous cell carcinoma overcame the biological resistance to neoplastic infiltration which probably exists in the otic capsule and the membranous labyrinth.