Chronic granulomatous abscess simulating cerebellopontine angle tumor.

The delayed development of brain abscess associated with a retained intracranial foreign body is not rare and has been documented [1-5] . We report an unusual case of chronic granulomatous abscess in the cerebellopontine angle region secondary to retention of a cotton ball during surgery for an acoustic neurinoma 20 years earlier. We describe the computed tomographic (CT) findings and emphasize that granulation tissue and abscess resulting from iatrogenic foreign body may simulate a mass lesion.