Two cases of Kaposi sarcoma

Case 1 :A 45-year-old Japanese man, who was diagnosed with acquired immunodeficiency syndrome (AIDS) with pneumocystis pneumonia, presented multiple violaceous plaques and nodules on his face, neck, and toes. Case 2 :An 84-yearold Japanese man without HIV infection developed a violaceous nodule on his dorsal foot after extensive chemotherapy for diffuse large B cell lymphoma. The lesion slowly became enlarged. Skin biopsies of both cases revealed a proliferation of spindle cells forming vascular slits in the dermis. Immunohistochemically, the tumor cells were positive for CD31, CD34, D2- 40, and LANA-1. We therefore diagnosed case 1 as AIDS-associated Kaposi sarcoma (KS) and case 2 as iatrogenic KS. Although its etiology remains unclear, KS is supposed to be a kind of opportunistic tumor occurring due to HHV-8 infection following severe immunosuppression caused by aging, drugs, and/or other viruses. We encountered four cases of AIDSassociated KS and one of iatrogenic KS in three years (2012-2014). We must be aware that KS can occur in individuals receiving immunosuppressive therapy.