Clinicopathological Characteristics of Kaposi`s Sarcoma and Usefulness of Detection of Human Herpes Virus 8

Abstract

Background: Kaposi’s sarcoma (KS) is a multicentric proliferative vascular tumor which involves cutaneous and visceral tissues. Recent study has clearly identified human herpes virus 8 (HHV8) in all Kaposi’s sarcoma patients, indicating that HHV8 is closely involved in the pathogenesis of Kaposi’s sarcoma.

Objective: The purpose of this study was to document clinical and histopathological features of KS and to emphasize the necessity of detection of HHV8 in the differential diagnosis of KS from other vascular lesions.

Methods: The medical records and histopathological slides of patients with KS diagnosed at Ajou University Hospital from January 1995 to December 2004 were reviewed. We performed immunohistochemical stain and polymerase chain reaction (PCR)-based analysis to detect HHV8 in KS and other vascular lesions.

Results: Among 12 patients, classic KS was found in 9 patients, AIDS-associated KS in 1 patient, and iatrogenic immunosuppressive KS in 2 patients. Patients with KS presented with various clinical features, showing purple- colored macules to nodules or tumors. Although lower extremities are most frequently involved sites, involvement of other sites such as arm and neck was noticed. Mucosal and systemic involvement was detected in AIDS- associated case. Immunohistochemical stains for HHV8 were positive in all KS, but they were negative in other vascular lesions. PCRs for HHV8 were positive in 8 of 11 (72.7%) KS, but they were negative in other vascular lesions. Classic KS responded well to surgical and radiation therapies and showed indolent course. Immunosuppressive KS regressed partially after dose reduction of immunosuppressive drug therapy, but the lesions persisted.

Conclusion: Immunohistochemical stain and/or PCR for HHV8 are useful means to differentiate KS from other vascular tumors.