Aids presenting with cutaneous Kaposi's sarcoma and bacillary angiomatosis in the bone marrow mimicking Kaposi's sarcoma

Kaposi's sarcoma (KS) and bacillary angiomatosis (BA) may be histologically similar. A precise diagnosis is required because of the different management of these diseases. KS or BA involving bone marrow is rare in patients with and without acquired immune deficiency syndrome (AIDS). We report the case of a 40-year-old human immunodeficiency virus (HIV)-positive homosexual male who presented with small KS lesions in the skin and BA in the bone marrow that histologically were similar. Laboratory evaluation revealed anemia and thrombocytopenia; CD4 count was 103/mm³, and the viral load was 750,000 HIV-1 mRNA copies per milliliter in plasma. Bartonella henselae, the etiologic agent of BA, was isolated from a blood culture. DNA sequences of human herpesvirus-8 (HHV-8), the putative etiologic agent of KS, were identified by polymerase chain reaction (PCR) in skin and bone marrow specimens, but antibody anti-HHV-8-encoded protein ORF73, localized signals only in the skin-KS lesion. The patient received clarithromycin and cefotetan for the BA, and antiretroviral therapy for the HIV infection. The skin lesions gradually regressed, the HIV-1 mRNA copy number decreased to less than 400 per milliliter and the CD4 lymphocyte count increased to 665/mm³. In conclusion, vascular lesions of BA and KS may be clinically and histologically similar, both may be associated with advanced AIDS, and an accurate diagnosis is required because of their different management.