SPINDLE-CELL PSEUDOTUMORS IN THE LUNGS DUE TO MYCOBACTERIUM-TUBERCULOSIS IN A TRANSPLANT PATIENT

A rare spindle cell pseudotumor in the skin, lymph nodes, and bone mar row has been previously reported in immunosuppressed transplant patien ts and patients with acquired immunodeficiency syndrome. All reported cases were caused by Mycobacterium avium-intracellulare or other nontu berculous mycobacteria. We are reporting spindle cell pseudotumors in the lungs caused by Mycobacterium tuberculosis. The patient had insuli n-dependent diabetes mellitus and was status post cadaveric renal and pancreatic transplants. His hospital course was complicated by pulmona ry tuberculosis due to M. tuberculosis. At autopsy, the lungs showed n umerous bilateral gray nodules ranging from 0.2 to 2.5 cm. Microscopic examination uncovered a cellular proliferation composed of spindle ce lls arranged in fascicles. There were no granulomata. An acid-fast sta in showed numerous acid-fast bacilli within the spindle cells. To our knowledge, this is the first case of spindle cell pseudotumor caused b y M. tuberculosis of the lungs. Awareness of this unusual manifestatio n of mycobacterial infection in immunosuppressed patients underscores the need for acid-fast staining of biopsies with spindle cell prolifer ation even in the absence of overt granulomatous lesions in order to p revent misdiagnosis.