African Kaposi Sarcoma
An 84-year-old Ethiopian woman presented with tender, violaceous, nonblanching nodules that had coalesced into plaques on the soles of both of her feet over the past 3 months. Similar discrete nodules were found on the dorsal aspect of her right wrist. She also had 2+ bilateral pitting edema up to her knees. The rest of the physical findings were unremarkable.
A thorough workup for the edema 6 months earlier had identified atrial fibrillation, and a therapeutic dosage of warfarin(Drug information on warfarin) was prescribed; no other cardiac abnormalities were found. Left ventricular ejection fraction estimated by echocardiogram was 65%.
Three years earlier, polymyalgia rheumatica (PMR) had been diagnosed, and a temporal artery biopsy was performed. Concern about possible giant cell arteritis associated with PMR prompted long-term treatment with prednisone(Drug information on prednisone) (40 mg/d).
Biopsy of the sole of the patient’s left foot revealed Kaposi sarcoma. The enlarging lesions most likely compressed nearby lymph vessels and caused the painful swelling of her lower legs.1 Results of HIV testing were negative.
Immunosuppression induced by either pharmacological agents or HIV can reactivate human herpesvirus 8 (HHV8), the infectious agent associated with all types of Kaposi sarcoma. Epidemiological studies have shown a 500-fold increase of Kaposi sarcoma in transplant patients and a 20,000-fold increase in patients with AIDS.2 Because Ethiopia is adjacent to regions where HHV8 infection is prevalent, it was concluded that this patient had African (endemic) Kaposi sarcoma, which was triggered by her age and chronic mild immunosuppression.3
The patient was subsequently referred for chemotherapy, and the prednisone dosage was tapered. This case highlights the potential effects of long-term immunosuppression in elderly patients from regions of Africa where Kaposi sarcoma is endemic.
1. Antman K, Chang Y. Kaposi’s sarcoma. N Engl J Med. 2000;342:1027-1038.
2. Hayward GS. Initiation of angiogenic Kaposi’s sarcoma lesions. Cancer Cell. 2003;3:1-3.
3. Dukers NH, Rezza G. Human herpesvirus 8 epidemiology: what we do and do not know. AIDS. 2003;17:1717-1730.