Kaposi's Sarcoma: A Clinico-Pathological Study of 21 Patients

Background: Kaposi's sarcoma (KS) is a mesenchymal tumor involving blood and lymphatic vessels. Viral oncogenesis by human herpesvirus 8 (HHV8) and cytokine-induced growth together with some state of immunocompromise represent important conditions for this tumor to develop. Objective: The purpose of this study was to document the clinical and histopathological features of KS in Korea. Methods: The medical records and histopathologic slides of patients with KS diagnosed at Yonsei University Medical Center from January, 1992 to March, 2003 were reviewed. We used immunohistochemical stains for HHV8 to determine whether HHV8 is present in KS. Results: 1. Among the 21 patients, classic KS was found in 7, acquired immunodeficiency syndrome (AIDS)-associated KS in 3, and iatrogenic, immunosuppressive KS in 11. 2. Classic and iatrogenic KS most often have a preference for the lower extremities, while the upper body in AIDS-KS. Mucosal involvement and systemic organ involvement could be detected in AIDS-KS. 3. Immunohistochemical stains for HHV8 were positive in 100% with classic KS and AIDS KS, and 90.9% with immunosuppressive KS. 4. Classic KS responded well to local therapy and showed indolent course. Iatrogenic, immunosuppressive KS generally regressed after reduction or cessation of immunosuppressive drug therapy, but some of them showed resistance to therapy. For AIDS-KS, no systemic treatments have been shown to prolong survival. Conclusion: Because classic KS and iatrogenic, immunosuppressive KS generally have a benign course, cautions are taken not to overtreat them. However, some cases of organ transplantation associated KS have an aggressive course, prompting us to consider active treatments to save transplanted organ.