Disseminated Mycobacterium malmoense infection in a patient with chronic granulocytic leukaemia

Mycobacterium malmoense is an atypical mycobacterium previously isolated from lymph nodes in children and from adults with pulmonary disease. Disseminated infection is extremely rare and bone marrow involvement has never previously been described. We report a patient with chronic granulocytic leukaemia and persistent fever with granuloma in the bone marrow due to disseminated M. malmoense infection. The patient initially received treatment with isoniazid, ethambutol and rifampicin with clearance of mycobacteria in the bone marrow and clinical improvement. Sensitivity in vitro was established for streptomycin, amikacin, ethambutol and rifabutin. The patient eventually expired as a result of progressive respiratory failure from other opportunistic infections. At autopsy staining of samples from lung parenchyma revealed fungal hyphi but staining for Pneumocystis carinii and myobacteria were negative.