Four Types of Kaposi Sarcoma
Four Types of Kaposi Sarcoma
A 46-year-old man with AIDS (CD4+ cell count, 150/μL) presented with a painful nodular lesion on the plantar surface of his right foot. The lesion had appeared 1 month earlier as a painless, 1-cm, raised, reddish purple nodule and had progressively enlarged to 5 cm. Six months earlier, the patient had cryosurgery to remove a similar, larger lesion on the posterior aspect of his right midcalf.
An excisional biopsy was performed. Microscopic examination of the biopsy specimen revealed endothelium- lined channels with scattered smaller blood vessels and vascular spaces admixed with macrophages, lymphocytes, and red blood cells; sheets of spindle cells were also present in the dermis and subcutaneous tissue. These findings were consistent with a diagnosis of Kaposi sarcoma.
Results of a stool culture, endoscopic biopsy, chest radiograph, and CT scan were all negative, ruling out extracutaneous disease.
Kaposi sarcoma is associated with human herpesvirus 8 infection and is the most common tumor in HIV-infected persons. In the United States, this low-grade vascular tumor is 20,000 times more common in persons with AIDS than in the general population.1 Although considered an AIDS-defining illness, Kaposi sarcoma can be seen at any stage of HIV infection, even in patients with normal CD4+ cell counts. AIDS-related Kaposi sarcoma is 1 of 4 epidemiological forms that include classic, African, and transplant-associated types.
Skin involvement is characteristic of AIDS-related Kaposi sarcoma, although extracutaneous spread to the oral cavity and GI and respiratory tracts is also common. Initially, the lesion may be a small, raised, reddish purple nodule (Box); a discoloration on the oral mucosa; or a swollen lymph node. The lesions are typically not painful or pruritic. They may present in 3 stages (patch, plaque, and nodule); they range in size from a few millimeters to several centimeters and appear most often on the lower extremities, face (especially the nose), oral mucosa, and genitalia.
Conditions that may mimic Kaposi sarcoma include angiokeratoma, bacillary angiomatosis, and pyogenic granuloma. Histologically, AIDS-related Kaposi sarcoma is characterized by the proliferation of spindle-shaped cells that express markers of both endothelial (vascular or lymphatic) and smooth muscle lineages. In addition, there are slit-like vascular spaces.2
There is no known curative therapy. The aim of treatment is to relieve symptoms, shrink the tumor, and prevent the progression of disease.3 HAART is used in almost all HIV-infected patients with Kaposi sarcoma.3-5 Topical retinoids, intralesional chemotherapy, cryotherapy, radiation therapy, and laser therapy can be used in patients with stable, limited, or relatively indolent disease. Systemic therapy, including chemotherapy, interferon-α, and biologics, is reserved for patients who have numerous lesions, lesions that are unresponsive to local therapy, or symptomatic visceral involvement.
1. Beral V, Peterman TA, Berkelman RL, Jaffe HW. Kaposi’s sarcoma among persons with AIDS: a sexually transmitted infection? Lancet. 1990;335:123-128.
2. Kumar V, Abbas AK, Fausto N, eds. Robbins and Cotran’s Pathologic Basis of Disease. 7th ed. Philadelphia: Elsevier; 2005:549-550.
3. Dezube BJ, Pantanowitz L, Aboulafia DM. Management of AIDS-related Kaposi sarcoma: advances in target discovery and treatment. AIDS Reader. 2004;14: 236-238, 243-244, 251-253.
4. International Collaboration on HIV and Cancer. Highly active antiretroviral therapy and incidence of cancer in human immunodeficiency virus-infected adults. J Natl Cancer Inst. 2000;92:1823-1830.
5. Ledergerber B, Telenti A, Egger M. Risk of HIV related Kaposi’s sarcoma and non-Hodgkin’s lymphoma with potent antiretroviral therapy: prospective cohort study. Swiss HIV Cohort Study. BMJ. 1999;319:23-24.
Early Presentation of HIV-Associated Kaposi Sarcoma
The abrupt onset of flat to slightly elevated, asymptomatic reddish to violaceous plaques and nodules (A and B) prompted a 28-year-old Hispanic man to seek treatment. He was ostensibly in good health.
Results of a biopsy revealed Kaposi sarcoma. The patient subsequently admitted to intravenous drug use and needle sharing— risk factors for HIV infection.
He was sent for retroviral serological screening and CD4+ cell count and referred to oncology for further evaluation and therapy. However, he failed to keep all scheduled appointments and was ultimately lost to follow-up.