Opportunistic fungal pneumonia

Opportunistic fungal infection is a common cause of serious morbidity and m ortality in immunocompromised patients. These infections occur primarily in patients with chemotherapy-induced neutropenia, acquired immunodeficiency syndrome, or immunosuppression after solid organ or bone marrow transplanta tion. The most important opportunistic fungal pathogens include Cryptococcu s neoformans, Candida and Aspergillus species, and the fungi that cause muc ormycosis. Opportunistic pneumonia caused by previously unrecognized pathog ens, such as Fusarium, Penicillium, and the dematiaceous fungi, an increasi ngly reported. The clinical and radiologic features of opportunistic fungal pneumonia are highly variable and often nonspecific. Diagnosis requires kn owledge of the various modes of presentation, radiologic manifestations, an d epidemiology of these infections. Because many of these organisms can col onize the upper airway, sputum cultures are considered diagnostically unrel iable. Instead, definitive diagnosis requires culture of the fungus from in fected tissue or demonstration of the organism on microscopic examination.