Mycobacterium simiae Infection in an Immunocompromised Patient without Acquired Immunodeficiency Syndrome

We report a case of lung infection due to Mycobacterium simiae in an immunocompromised patient without acquired immunodeficiency syndrome. The patient had multiple pulmonary nodules similar to those seen in cases of lung disease caused by Mycobacterium avium in elderly women. Appropriate therapy for M. simiae disease should be determined because, in some cases, the risk of adverse effects can outweigh the potential benefits of treatment.