Mycobacterial spindle cell pseudotumor of the lung.

Mycobacterial spindle cell pseudotumor (MSP) is a rare benign lesion characterized by local proliferation of spindle-shaped histiocytes containing acid-fast mycobacteria. Most reported cases of MSP occur in the lymph nodes, skin, spleen, and brain in patients who are immunocompromised, particularly following solid organ transplant and in those with AIDS. This is a case report of a patient with AIDS who presented with cough, generalized weakness, and fatigue, who was found to have multilobar lung masses that were MSP, which to our knowledge has not yet been reported in the literature.