Non-AIDS Kaposi sarcoma
Classic (traditional) KS is seen almost exclusively in people of Mediterranean and Ashkenazi Jewish descent, with age of onset typically between 50 and 70 years. Older literature described classic KS occurring more often in males, with a male-to-female ratio of approximately 12:1. However, more recent studies suggest that the sex gap may not be so significant.
Classic Kaposi sarcoma most commonly runs an indolent course for 10-15 years or more, with slow enlargement of tumors and the gradual development of additional lesions. After many years, systemic lesions can develop along the gastrointestinal tract, in lymph nodes, and in other organs. These visceral tumors are usually asymptomatic. Up to one-third of the patients with classic KS develop a second primary malignancy, most frequently non-Hodgkin lymphoma.
There is an aggressive endemic form in equatorial black African individuals that is also unrelated to AIDS. Areas of highest prevalence include Uganda, the Congo Republic, Zambia, and Congo (Brazzaville). Systemic lesions are particularly prevalent in this form. The male-to-female ratio is nearly equal among children but increases with age.
Iatrogenic KS is the result of long-term systemic immunosuppression and is common in organ transplant recipients, especially renal. It may resolve when immunosuppressive medications are discontinued. This variant is mostly limited to the skin, with infrequent visceral involvement.
C46.0 – Kaposi's sarcoma of skin
109386008 – Kaposi's sarcoma of skin
- Angiosarcoma – Usually occurs on the head and neck.
- Prurigo nodularis
- Hypertrophic lichen planus
- Dermatofibroma or dermatofibrosarcoma protuberans
- Cat-scratch fever – Has a similar vascular proliferation clinically (bacillary angiomatosis).
- Single lesions with rapid onset are consistent with a lobular capillary hemangioma (pyogenic granuloma).
- Lichen simplex chronicus
- 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 or port-wine stain.