Case of the month: February 1998--82 year old man with progressive visual defects.

An 82 year old man with a recurrent prolactin-secreting pituitary adenoma had clinically asymptomaptic fungal growth in necrotic tissue adjacent to the tumor. This fungus was characterized by clumps of basophilic hyphae with pigment production. Ascus formation containing nucleated conidiopores was present. The asci had tapered and cylindrical beaks making Microascus sp. the most likely diagnosis, however, without cultures, Pseudoallesheria boydii could not eliminated. The patient was treated with Amphotericin B and there was no evidence of intracranial extension 4 months later.