Chronic blastomycotic meningitis.

Three cases of blastomycosis which presented as chronic meningitis are reported. Blastomycotic meningitis is an uncommon form of chronic fungal meningitis and is difficult to diagnose during life unless the patient has obvious systemic blastomycosis elsewhere. Evaluation of cerebrospinal fluid obtained by lumbar tap is usually not diagnostic. Obstructive hydrocephalus developed in all three patients during the course of their fungal meningitis. Culture of ventricular fluid yielded the fungus in all three patients (although only after death in one case). One patient received only minimal therapy before death whereas the third patient received a full course of amphotericin B with restoration to his premorbid state. Blastomycosis should be included in the differential diagnosis of chronic meningitis and, when suspected, the cisternal or ventricular fluid should be sampled.