Primary intraosseous AIDS-associated Kaposi's sarcoma. Report of two cases with initial jaw involvement.

AIDS-associated Kaposi's sarcoma (KS), which in 80% of cases occurs in the oral cavity, usually presents with characteristic clinical features such as brown-bluish pigmented macules or tumorous lesions. In later stages the tumor, most probably originating from the vascular endothelium, may secondarily induce erosion of the underlying bone. The primary, intraosseous occurrence of KS has prompted the present 2 case reports. The tumor presented as extensive, diffuse osteolysis within the mandible without causing clinical symptoms. Although rare, intraosseous KS must be included in the differential diagnosis of isolated bone defects in HIV-infected patients.