An 84-year-old woman is referred for evaluation of 2 skin lesions — a nodular growth on her back that is clinically diagnosed as basal cell carcinoma and a 0.8-cm deeply pigmented papule on her right shin that was first noted 4 months ago. The growth is often caught on her clothing and bleeds when traumatized. Her medical history indicates hypertension, coronary artery disease, and stasis dermatitis.
Submit your diagnosis to see full explanation.
Kaposi sarcoma is a vascular neoplasm caused by the human herpesvirus 8 (HHV8). The link between Kaposi sarcoma and HHV8 was first identified by Chang et al in 1994.1 Several clinical forms of this malignancy have been identified, including a large subset associated with poorly controlled HIV.2,3 Kaposi sarcoma remains one of the most common AIDS-defining malignancies.4
This case illustrates the “classic” form of Kaposi sarcoma that occurs on the lower extremities of individuals who are of Mediterranean or Eastern European descent. Men aged >50 years are most frequently affected. Secondary malignancies may often be found in association with Kaposi sarcoma.3
Kaposi sarcoma may present as violaceous to erythematous macules, plaques, or nodules depending on the stage of development. Diagnosis is made by histology, which reveals spindle cell proliferation, vascular channels, and extravasated red blood cells.4 Mitotic figures increase as the disease advances. The presence of HHV8 can be confirmed by immunohistochemistry.5
Classic Kaposi sarcoma usually has a more indolent course and, in an elderly patient, may not require intervention. Isolated lesions may be surgically excised, treated with cryosurgery, or injected with vincristine.6 Full resolution has also been reported with topical imiquimod.7
Sara Mahmood, DPM, is a podiatric dermatology fellow at St Lukes University Health Network and DermDox Center for Dermatology. Stephen Schleicher, MD, is director of the DermDox Center for Dermatology in Pennsylvania, as well as an associate professor of medicine at Commonwealth Medical College and a clinical instructor of dermatology at Arcadia University and Kings College.
1. Chang Y, Cesarman E, Pessin MS, et al. Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi’s sarcoma. Science. 1994;266(5192):1865-1869.
2. Goncalves PH, Ziegelbauer J, Uldrick TS, Yarchoan R. Kaposi sarcoma herpesvirus-associated cancers and related diseases. Curr Opin HIV AIDS. 2017;12(1):47-56.
3. Iscovich J, Boffetta P, Franceschi S, Azizi E, Sarid R. Classic Kaposi sarcoma: epidemiology and risk factors. Cancer. 2000;88(3):500-517.
4. Radu O, Pantanowitz L. Kaposi sarcoma. Arch Pathol Lab Med. 2013;137(2):289-294.
5. Mariggiò G, Koch S, Schulz TF. Kaposi sarcoma herpesvirus pathogenesis. Philos Trans R Soc Lond B Biol Sci. 2017;372(1732):20160275.
6. Bishop BN, Lynch DT. Cancer, Kaposi Sarcoma. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2020.
7. Gündüz K, Günay U, Inanir I, Gençoğlan G, Temiz P. Efficacy of 5% imiquimod cream in a patient with classic Kaposi sarcoma. J Dermatol Case Rep. 2012;6(2):52-53.