Granulomas in acquired immunodeficiency syndrome-associated cutaneous Kaposi sarcoma: evidence for a role for Mycobacterium tuberculosis.

Background: Co-lesional acquired immunodeficiency syndrome-associated cutaneous Kaposi sarcoma (AIDS-KS) and Mycobacterium tuberculosis-associated granulomatous inflammation are undocumented.

Method: Retrospective appraisal of skin biopsies with co-lesional AIDS-KS and microscopic tuberculosis (TB).

Results: Sixteen biopsies from nine males and seven females form the study cohort. Histological assessment confirmed nodular and plaque KS in 12 and 4 cases each, respectively. Necrotizing, non-necrotizing and a combination of necrotizing and non-necrotizing granulomatous inflammation were present in nine, two and five biopsies each, respectively. The identification of acid fast bacilli on Ziehl-Neelsen staining and M. tuberculosis on polymerase chain reaction confirmed co-lesional TB in 15/16 biopsies. Co-lesional AIDS-KS and lichen scrofulosorum, hitherto undocumented, were confirmed in one biopsy. The histopathological findings served as a marker of human immunodeficiency virus (HIV) infection, visceral TB, therapeutic noncompliance and multidrug resistant pulmonary TB in nine, eight, five and one patient, respectively. M. tuberculosis was cultured from sputum or nodal tissue of all patients.

Conclusion: Granulomatous inflammation in KS requires optimal histopathological and molecular investigation to confirm an M. tuberculosis origin. The cutaneous co-lesional occurrence of AIDS-KS and microscopic TB may serve as the sentinel clue to HIV infection, systemic TB, therapeutic noncompliance or multidrug resistant TB.