Actinomycotic brain abscess.

Actinomycosis is caused by Gram-positive filamentous anaerobic organisms of genus Actinomyces, which are commensals of mucosal membranes of the oropharyngeal cavity, and gastrointestinal and genitourinary tracts. Central nervous system involvement is rare and may present as cerebral abscess, meningitis, meningoencephalitis, subdural empyema or epidural abscess. The radiological appearances of actinomycotic brain abscesses are not well recognized. Here, we present the characteristic imaging features of an actinomycotic brain abscess.