AIDS-associated Kaposi sarcoma
The outbreak of KS among young, previously healthy men who have sex with men (MSM) heralded the recognition of AIDS in 1981. AIDS-associated KS is the most common neoplasm in HIV-seropositive patients. It is an AIDS-defining illness. This form of KS disproportionately affects MSM, African Americans (regardless of sexual orientation), and heterosexual African individuals. KS lesions have been reported in up to 35% of AIDS patients and are seen more commonly in those with CD4 counts less than 150-200 cells/mm3.
Patients with AIDS-associated KS often have multifocal cutaneous disease. Around 20% of patients will have concomitant visceral involvement, which places these patients at risk for hemorrhage from gastrointestinal lesions, cardiac tamponade, and pulmonary obstruction. Additionally, AIDS-associated KS is more likely than classic KS to display a rapidly progressive course.
Spindle cells of endothelial origin are the predominant cell affected. In the latent phase, HHV-8 antigens promote cell proliferation by inactivating the RB gene, which leads to transcription of S-phase genes and blocks apoptosis via p53 and p27Kip1 suppression. In the lytic phase, when tumour formation is noted, thousands of virion particles are assembled resulting in cell lysis. HHV-8 requires additional co-factors for the development of KS. HIV co-infection acts as a stimulant for HHV-8 viral lytic expression and via its suppression of the immune system.
The introduction of highly active antiretroviral therapy (HAART) dramatically decreased the incidence, morbidity, and mortality of AIDS-associated KS.
For discussion of classic, endemic, and iatrogenic forms, see Non-AIDS Kaposi sarcoma.
C46.0 – Kaposi's sarcoma of skin
420524008 – Kaposi's sarcoma associated with AIDS
- Bacillary angiomatosis
- Lobular capillary hemangioma (pyogenic granuloma)
- Cherry hemangioma
- Lichen simplex chronicus
- Prurigo nodularis
- Metastatic carcinoma or melanoma
- Pigmented basal cell carcinoma
- Blue rubber bleb nevus syndrome
- Tufted angioma
- Cavernous hemangioma
- Arteriovenous malformation
- Leukemia cutis
- Early KS may resemble a large junctional nevus, a port-wine stain, or an ecchymosis.
Last Updated: 10/27/2017