Snapshot A 60-year-old man presents to his primary care physician reporting unintentional weight loss, night sweats, and fevers. He complains of a “strange” rash on his face that bothers him cosmetically. The rash does not hurt or itch. On exam, there are multiple well-demarcated red or purple macules and papules. He has a history of risky behaviors, including IV drug use and unprotected intercourse with multiple partners. His CD4 count comes back at 100/mm3. Introduction Malignancy of lymphatic endothelial cells Commonly affects skin lungs lymph nodes GI (especially in AIDS patients) epidemiology Epidemiological subsets AIDS most common AIDS-associated malignancy commonly seen in AIDS acquired through sexual contact rarely seen in AIDS acquired through injection drug use immunosuppression post-transplant classic sporadic usually in older men in people of Mediterranean origin endemic Eastern Africa Southern Africa 50% of childhood soft tissue tumors due to Kaposi’s sarcoma etiology Pathogenesis human herpes virus 8 genetic predisposition in some Presentation Symptoms B symptoms (fevers, night sweats, weight loss) painless skin lesions may have pain associated with internal lesions Physical exam red or purple lesions of varying morphologies macules/patches papules/plaques nodules common on face, oral mucosa, legs, and torso lymph nodes may be enlarged Differential Diagnosis Melanoma Bacillary angiomatosis Pyogenic granuloma diagnosis Diagnosis by clinical exam Diagnosis confirmed with skin biopsy neoplastic spindle-shaped cells that form clefts and vascular channels Do CD4 count if AIDS is suspected Treatment Prevention highly active anti-retroviral therapy for those with HIV infections annual skin exam in those at risk Anti-retroviral therapy majority will resolve Injection of vincristine or interferon If the above fail chemotherapy doxorubicin/daunorubicin paclitaxel etoposide radiation Discontinue any immunosuppressants Complications Metastatic progression Prognosis Slow progression