Pneumonia in hairy-cell leukemia.

Abstract
Hairy-cell leukemia (HCL) is an unusual malignant hematologic disorder involving splenomegaly, pancytopenia and circulating mononuclear cells with prominent cytoplasmic projections. As in most forms of leukemia, the risk of pulmonary infection by normal pathogens and opportunistic invaders alike is high. HCL may be associated with granulomatous infections of the lung, especially mycobacterioses. Of 33 patients, 9 had a fungal or mycobacterial infection, including 5 atypical mycobacterial species. Five of the 6 patients with mycobacterioses and 1 of the 3 with fungal pneumonia survived the infection with appropriate therapy. Granulomatous infections, particularly mycobacterioses, should be seriously considered in the differential diagnosis of pulmonary parenchymal disease in a patient with HCL.