Mycobacterial Pseudotumor

Mycobacterial Pseudotumor

Elizabeth A. Montgomery, MD

Hematoxylin & eosin at low magnification of a mycobacterial spindle cell tumor shows a loosely lobulated proliferation of epithelioid cells with a background of lymphoplasmacytic cells.

Acid-fast bacteria stain highlights numerous organisms in the proliferating spindled histiocytes image. The diagnosis is easy to make as long as it is considered.



  • Exuberant spindle cell lesion, usually involving lymph nodes, induced by mycobacteria



  • Immunocompromised patients

    • Majority have AIDS

      • Often also have evidence of systemic infection with Mycobacterium avium complex organisms

    • Examples reported in individuals with immune comprise from entities other than AIDS

      • e.g., lupus on long-term steroid treatment

    • Seldom encountered in USA recently since many patients are better treated for their HIV disease

      • Reports peaked in early 1990s


  • Drugs

    • Antimycobacterial drugs


  • Good after treatment of infection

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Mycobacterial Pseudotumor

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