Admissions Ad Nauseum: A Cryptic Case of Chiasmopathy

Examination of the CSF on the final LP revealed yeast forms on the gram stain consistent with Cryptococcal neoformans. Cryptococcal antigen titre was 1: 512. Amphotericin B and Flucytosine were started IV with high dose IV steroids. With treatment, acuity, color vision and fields all returned to normal. Cryptococcal antigen of the CSF from the initial LP was negative. However, a mucicarmine stain of the pituitary biopsy was positive, consistent with the presence of mucopolysaccharides on the capsule of cryptococcal yeast at the time of the biopsy. It remained unclear as to whether the primary diagnosis was cryptococcal meningitis in an immunocompetent host, or if instead, a fungal meningitis complicated a case of neurosarcoidosis in the context of immunosuppression secondary to IV steroids. The speciation of the yeast was Cryptococcus neoformans var grubii, commonly found in eucalyptus plant, wood and pigeon feces and found around the world. Inoculation may have occurred via trans-sphenoidal biopsy, as Cryptococcus is usually acquired via inhalation of spores. Biopsy could have introduced fungal elements into the CNS. HIV was negative (tested twice), but CD4 counts were decreased. In culture growth occurs in 3-7 days with identification in 3-4 days; however occasionally growth is slower and incubation should be continued for 4-6 weeks. Cryptoccocus neoformans is a saprophytic fungus that may cause disease in normal hosts as well as the immunocompromised. In the immunocompetent individuals Cryptococcus neoformans var. gattii is implicated more often compared to the immunocompromised with Cryptococcus neoformans var neoformans. In those who are immunocompromised with defective cell mediated immunity, such as those being treated with corticosteroids, HIV, lymphoma and leukemic patients, infections can be more serious with rapid progression and dissemination. Infections are more often pulmonary than meningoencephalitis. In the immunocompetent infections are usually of the basal leptomeninges.