Intracerebral abscess due to Cutibacterium acnes after lung transplantation

Cutibacterium (C) acnes, a Gram-positive bacterium that is part of the commensal flora, is increasingly noticed as an opportunistic pathogen in serious infections in both immunocompromised and immunocompetent patients. The indolent character and often difficult identification because of its slow growth contribute to delayed diagnosis or underdiagnosis. This report highlights a unique case of a lung transplant recipient with a C acnes intracerebral abscess, and we recommend including this organism in such differential diagnosis. A 66-year-old woman, 2 years after bilateral lung transplantation for chronic obstructive pulmonary disease, presented with frontal headache, without other complaints, and with normal neurological examination. Magnetic resonance imaging showed an extensive lesion in the right frontal lobe with extensive perilesional edema. Given the broad differential diagnosis, stereotactic brain biopsy was performed and culture became positive for C acnes. She was treated with intravenous ceftriaxone for 8 weeks and per oral clindamycin for 6 months, as well as corticosteroids in tapered dose. There was a rapid favorable clinical and radiographic evolution.