Suppurative inflammation with microabscess and pseudocyst formation is a characteristic histologic manifestation of cutaneous infections with rapid-growing Mycobacterium species

Am J Clin Pathol. 2008 Oct;130(4):514-7. doi: 10.1309/DPCLAWWQNTB74JNB.

Abstract

Mycobacterial infections of the skin classically cause a granulomatous tissue reaction. We have observed a suppurative pattern of inflammation associated with infections by rapid-growing Mycobacterium species in immunocompromised patients. We report 6 cases in skin and soft tissue with an unusual but consistent lack of a predominance of granulomatous inflammation. Of the 6 cases, 4 had predominantly (approximately 75%) suppurative inflammation, 1 case predominantly demonstrated (approximately 75%) a mix of acute and chronic inflammation, and 1 case showed an approximately equal contribution of suppurative and granulomatous inflammation. All 6 cases showed abscess formation and numerous acid-fast bacilli (AFB) on AFB stain and were confirmed by tissue culture. Of these 6 cases, 2 had microabscesses with central pseudocysts harboring microorganisms. Five patients were taking oral prednisone, and 1 had an uncharacterized immunodeficiency. These cases highlight the need for awareness of this unusual manifestation of infection with rapid-growing Mycobacterium species, particularly in immunocompromised patients.

MeSH terms

  • Abscess / immunology
  • Abscess / microbiology
  • Abscess / pathology*
  • Aged
  • Anti-Inflammatory Agents / adverse effects
  • Female
  • Humans
  • Immunocompromised Host*
  • Immunologic Deficiency Syndromes / complications
  • Immunologic Deficiency Syndromes / immunology
  • Inflammation / immunology
  • Inflammation / microbiology
  • Inflammation / pathology*
  • Male
  • Middle Aged
  • Mycobacterium Infections / immunology*
  • Mycobacterium Infections / pathology
  • Prednisone / adverse effects
  • Skin Diseases, Bacterial / immunology
  • Skin Diseases, Bacterial / microbiology
  • Skin Diseases, Bacterial / pathology*
  • Suppuration / immunology
  • Suppuration / microbiology
  • Suppuration / pathology

Substances

  • Anti-Inflammatory Agents
  • Prednisone