What is kaposi sarcoma?

• Vascular neoplasm caused by human herpes virus 8 (HHV8) • Four forms: Chronic (older Ashkenazi Jewish males), African, transplant-associated, AIDS-associated • Tends to be indolent but may be locally aggressive • Skin is predominant site • May also affect lymph nodes, visceral organs or mucosa • Excision can be curative • Infiltrative proliferation of spindled endothelial cells • Slit-like vascular spaces formed by spindled endothelial cells with minimal to moderate atypia. • Extravasated erythrocytes and hemosiderin are key histologic clues