Details
Eyelid lesion.
Kaposi sarcoma is an intermediate grade vascular neoplasm caused by human herpes virus-8. Four clinical variants have been described: 1) classic: an indolent form typically occurring in the legs and feet of elderly men; 2) endemic: children and adults in Africa; 3) iatrogenic: immunosuppressed patients of any age; 4) AIDS-associated: an aggressive and often disseminated form.
Microscopic examination reveals a neoplasm composed of infiltrating and interconnecting fascicles of spindle cells filled with blood. There is relatively mild to moderate atypia and occasional mitotic figures. A background of inflammatory cells is present. Intracytoplasmic hyaline globules (thought to be degenerated erythrocytes) can be found within the spindle cells. Immunohistochemical stains (not shown) demonstrated the cells to be CD31, ERG, CD34 and HHV8 positive.