Presentation and Pathogenesis of Kaposi Sarcoma

Abstract

Kaposi sarcoma (KS) is a vascular neoplasm caused by infection with human herpesvirus 8 (HHV-8). Epidemic KS is found among persons with HIV infection; it is the most common malignancy in persons with HIV worldwide. Two decades after HHV-8 was first identified, much is now known about how chronic infection leads to the development of KS. HHV-8 is likely transmitted via saliva in most cases. The virus, host, and possibly environmental factors all contribute to the risk of developing KS. Heterogeneous clinical manifestations of the disease feature skin and mucous membrane involvement in adults, with advanced disease involving the thoracic or abdominal viscera. Pediatric KS is unusual outside of sub-Saharan Africa, but is typically characterized by lymph node and cutaneous disease. KS also may be the presenting manifestation of an immune reconstitution inflammatory syndrome after HIV-infected patients initiate antiretroviral therapy, and can be co-morbid with other HHV-8-associated diseases including multicentric Castleman disease and primary effusion lymphoma. For patients with access to ART and/or chemotherapy, survival after a diagnosis of KS is excellent, but clinical responses to therapy are often incomplete and new therapies for the disease are needed.