• Classic Kaposi’s sarcoma or epidemic type (Fig. 108.1B): initially described in Jews; indolent; found on the legs of elderly men; confined to the skin and may be present for decades; not fatal.

• African variety or endemic type (Fig. 180.2): violaceous skin plaques, black under Negroid skin; this is an aggressive invasive tumour that is ultimately fatal. It occurs in children and younger men. In the former it is often associated with generalized lymphadenopathy.

• AIDS-associated Kaposi’s sarcoma (Fig. 180.3): found in approximately one-third of patients with AIDS and more common in homosexuals. The cutaneous lesions respond to interferon-alfa and cytotoxic chemotherapy. About one-third develop a second malignancy such as lymphoma, myeloma or leukaemia. Patients eventually die from a secondary infection seen in AIDS rather than as a direct consequence of Kaposi’s sarcoma.

• Transplantation-associated Kaposi’s sarcoma, particularly in patients on high-dose immunosuppressive therapy; these often regress when therapy is stopped. Transmission of human herpesvirus 8 infection occurs from renal transplant donors to recipients and is a risk factor for Kaposi’s sarcoma (N Engl J Med 1998;339:1358–63).

• Early or ‘patch’ stage: similar to granulation tissue and characterized by jagged, thin-walled, dilated vascular spaces in the epidermis with interstitial inflammatory cells and extravasated red cells (with haemosiderin deposition)

• Plaque stage

• Later or ‘nodular’ lesions: features are more characteristic at this stage and comprise spindle-shaped stromal cells with irregular slit-like spaces filled with red blood cells and lined by recognizable endothelium, intertwined with normal vascular channels.

• Baseline treatment includes a retroviral agent such as zidovudine, which has no direct effect on Kaposi’s sarcoma but diminishes the degree of immunosuppression (note: eczema, xerosis, warts and Kaposi’s sarcoma are associated with HIV infection but do not improve with antiretroviral therapy). Retinoic acid is a promising alternative.

• Localized mucocutaneous lesions respond well to liquid nitrogen, radiotherapy, cryotherapy, surgical excision, intralesional vinblastine or sclerosing solutions, bleomycin or interferon-alfa.

• Interferon-alfa as systemic treatment is effective in 40–50% of patients with indolent Kaposi’s sarcoma, a CD4 cell count >400 × 10⁶ cells/l, few systemic symptoms and no opportunistic infections.

• Radiation therapy.

• Combination therapy of surgery, chemotherapy and radiation or with chemotherapy alone.

• Relatively marrow-sparing chemotherapy (bleomycin, vincristine or low-dose liposomal doxorubicin) is used when other treatment fails in patients with aggressive Kaposi’s sarcoma (Lancet 1997;350:1363). Complete or partial remission may be obtained in >75% of those with Kaposi’s sarcoma; shorter survival is associated with low CD4 cell count.