Mycobacterial spindle cell pseudotumor of lymph nodes.

Two cases of spindle cell pseudotumor in the lymph nodes of patients with acquired immunodeficiency syndrome caused by mycobacterial infection are reported and the literature reviewed. The lesions mimicked neoplasms because they were composed predominantly of spindle cells arranged in a storiform pattern. Most of the spindle cells were phagocytic cells that contained large amounts of mycobacteria. It is important for the pathologist to recognize the lesion so that a prompt tissue diagnosis can be provided because specific therapy is available.