Pulmonary Cryptococcosis

Cryptococcosis is an invasive fungal infection (IFI), caused predominantly by Cryptococcus neoformans or Cryptococcus gattii, that affects both immunocompromised (IC) and non-IC patients. Although the most serious disease manifestation is meningoencephalitis, cryptococcal pneumonia is underdiagnosed and may disseminate to the central nervous system (CNS) and other sites depending upon host defenses and administration of appropriate antifungal therapy. The clinical presentation of pulmonary cryptococcosis varies along a spectrum from asymptomatic infection to severe pneumonia and respiratory failure, and the radiological presentation can be characterized by an array of findings, including nodules, consolidation, cavitary lesions, and a diffuse interstitial pattern. Diagnosis most often relies upon isolation of Cryptococcus from a pulmonary specimen in the appropriate clinical and radiological context. Treatment recommendations include induction therapy with an amphotericin B preparation and flucytosine for IC patients and those with severe disease and fluconazole for mild-to-moderate, localized disease. Knowledge of the pathophysiology, epidemiology, clinical presentation, and treatment of pulmonary cryptococcosis may lead to greater recognition of this underdiagnosed IFI and improved outcomes.