Pseudo - Kaposi Sarcoma : Differential Diagnosis from Kaposi Sarcoma = Pseudo - Kaposi Sarcoma : Differential Diagnosis from Kaposi Sarcoma

다국어 초록 (Multilingual Abstract)

Background: Pseudo-Kaposi sarcoma mimicks Kaposi sarcoma, both clinically and histopathologically. These conditions are due to congenital (Stewart-Bluefarb syndrome) or acquired (Mali) vascular malformations. Objectives: The purposes of this study were aimed at evaluating the clinical and histopathological characteristics of pseudo-Kaposi sarcoma and finding differential diagnostic tools from Kaposi sarcoma. Methods: Clinical information of 7 patients with pseudo-Kaposi sarcoma diagnosed in Asan Medical Center from 1989 to 1999 was obtained from the medical records and clinical follow-ups. We re-evaluated 10 biopsy specimens obtained from them and immunohistochemical studies for cutaneous lymphocyte antigen (CLA), CD34, vimentin, and factor Ⅷ were performed with the standard streptavidin-biotin method using paraffin-embedded tissue specimens of 7 pseudo-Kaposi sarcomas and 3 Kaposi sarcomas. In addition, we examined whether human herpesvirus 8 (HHV8) was detected in 3 patients by polymerase chain reaction (PCR). Results: Six male and one female patients were included. Mean age was 36.3 years. Three patients were classified into Mali type and the other four patients were into Stewart-Bludfarb type. Histopathological examinations revealed capillary proliferation in the upper dermis, perivascular infiltrate of inflammatory cells, extravasated red blood cells, and fibrosis of dermis. Anti-factor Ⅷ and CD34 stained endothelial cells only. CLA was expressed in lymphocytic infiltrate in the epidermis and dermis of pseudo-Kaposi sarcoma, whereas it was negative in Kaposi sarcoma. PCR for HHV 8 showed negative results. Conchcsions: Pseudo-Kaposi sarcoma is an uncommon entity with characteristic clinical and histopathological features. Differential diagnosis between Pseudo-Kaopsi sarcoma and Kaposi sarcoma is important. We suggest that detection of HHV 8 by PCR and imunohistochemical study for CLA may be effective tools in the differential diagnosis between them. (Ann Dermatol 12(2) 83~89,2000).