Four Types of Kaposi Sarcoma

•AIDS-Related Kaposi Sarcoma •Classic Kaposi Sarcoma•Transplant-Associated Kaposi Sarcoma•African Kaposi Sarcoma

AIDS-Related 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.

REFERENCE:
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.

•AIDS-Related Kaposi Sarcoma •Classic Kaposi Sarcoma•Transplant-Associated Kaposi Sarcoma•African Kaposi Sarcoma

Classic Kaposi Sarcoma

For 1 month, a 66-year-old man had had an asymptomatic lesion on the dorsum of his left hand. The flesh-colored, dome-shaped, maroon-crusted lesion measured 0.7 cm and was located over the fourth knuckle. The patient had chronic obstructive pulmonary disease but was otherwise in good health. He was seronegative for HIV.

The lesion was excised; pathological examination revealed atypical vascular proliferation in the dermis featuring spindle-shaped cells with vascular slits and extravasation of erythrocytes. Mitotic activity was present, and cytoplasmic inclusion bodies were also noted.

Classic Kaposi sarcoma was diagnosed in light of the patient’s age and the absence of AIDS. The classic form is rare; most often, men of Jewish, Greek, or Italian descent who are in the fifth to seventh decades of life are affected. Typically, eruptions occur on the extremities, especially the legs and feet. Edema may precede or follow the appearance of lesions. Spontaneous regression can occur; generally the disease progression is chronic and slow. The lymph nodes and viscera may become involved; however, death usually results from an unrelated cause.

The lesions of classic Kaposi sarcoma are generally asymptomatic, although pain or pruritus may occur. In addition to excision, liquid nitrogen, radiation, and intralesional vinblastine may be used to remove lesions.

•AIDS-Related Kaposi Sarcoma •Classic Kaposi Sarcoma•Transplant-Associated Kaposi Sarcoma•African Kaposi Sarcoma

Transplant-Associated Kaposi Sarcoma

Kaposi sarcoma was diagnosed in a 54-year-old woman who had had a renal transplant. These multiple purple patches, plaques, and nodules abruptly appeared on the patient’s abdomen when she was taking prednisone and azathioprine.

Biopsy revealed Kaposi sarcoma not only in the skin but also in an enlarged inguinal lymph node. This case illustrates the association between the tumor and an immunosuppressed state. The patient received chemotherapy

•AIDS-Related Kaposi Sarcoma •Classic Kaposi Sarcoma•Transplant-Associated Kaposi Sarcoma•African Kaposi Sarcoma

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 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 (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.

REFERENCES:
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.