Pituitary apoplexy as a mimicker of infectious meningitis in an adolescent female patient.

Pituitary apoplexy can cause a chemical meningitis and its mimicry in presentation with infectious meningitis poses a diagnostic challenge. Here we report an 18-year-old woman who presented with acute headache, altered mental status, and cerebral spinal fluid (CSF) pleocytosis, and clinically improved with antibiotics and steroids. Despite an unremarkable head computed tomography scan, brain magnetic resonance imaging showed a pituitary macroadenoma with apoplexy. This is one of the first reports of an adolescent with pituitary apoplexy masquerading as infectious meningitis and underscores the importance of keeping this rare condition, often missed on CT scans, on the differential for CSF pleocytosis.