Gastrointestinal: Kaposi's sarcoma

Abstract

Kaposi's sarcoma takes the name of a Hungarian dermatologist, Dr Moritz Kaposi, who described 5 men with multiple pigmented sarcomas of the skin in 1872. Several clinical variants have been described. In the classic variant, multiple cutaneous lesions progress up the arms and legs over a period of years or decades. In early reports, the disorder was largely restricted to elderly men from eastern and southern Europe but, in the 1950's, increasing numbers of patients were identified in several countries in Africa. By the 1980's, more aggressive variants were described that were subsequently associated with the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome (AIDS). Kaposi's sarcoma has also been associated with organ transplantation and with use of immunosuppressive drugs for a variety of medical disorders. There is now persuasive evidence that Kaposi's sarcoma is induced by a herpes virus (human herpesvirus 8). In Kaposi's sarcoma associated with AIDS, most but not all patients have cutaneous lesions. Other affected sites include the oral cavity, gastrointestinal tract, lymph nodes and viscera. An unusual feature in the patient illustrated below was the presence of Kaposi's sarcoma in lesions that mimicked anal condylomas. A 41-year-old man with AIDS and Kaposi's sarcoma was admitted to hospital with Salmonella bacteremia. He had a CD4 count of 46/mm3 but had not been previously treated with antiretroviral therapy. On examination, he had many raised violacious plaques on his trunk, face and extremities typical of Kaposi's sarcoma (Fig. 1). He also had perianal masses that had the appearance of prominent anal condylomas (Fig. 2). However, biopsy and excision of the perianal lesions revealed both condylomas and Kaposi's sarcoma. At sigmoidoscopy, there were additional submucosal vascular lesions typical of involvement of the lower rectum. Although involvement of the gastrointestinal tract by Kaposi's sarcoma can be demonstrated in at least 40% of patients, many of these patients are asymptomatic. Furthermore, endoscopic investigations are usually unnecessary as gastrointestinal involvement does not appear to have a significant influence on prognosis. Because of this, formal evaluation of the gastrointestinal tract is only recommended in those patients with symptoms such as abdominal pain, gastrointestinal obstruction or bleeding. The treatment of Kaposi's sarcoma associated with AIDS consists of antiretroviral treatment and chemotherapy. Contributed by