Magnetic resonance imaging findings in AIDS patients with central nervous system cryptococcosis.

Cryptococcosis is an opportunistic fungal infection caused by Cryptococcus neoformans. Generally, the disease affects the central nervous system, especially in patients with human immunodeficiency virus infection. Central nervous system involvement can be either meningeal or parenchymal. As the infection spreads along the Virchow-Robin spaces these structures may dilate with the mucoid and gelatinous material produced by the organism's capsule. The lesions associated with the dilatation of Virchow-Robin spaces are referred to as gelatinous pseudocysts. Bigger lesions are known as cryptococcomas. In this article we describe five patients with neurocryptococcosis associated with AIDS and parenchymal lesions compatible with gelatinous pseudocysts and cryptococcomas.