Immunohistochemical Analysis of Procathepsin L and Cathepsin B in Cutaneous Kaposi's Sarcoma

The study investigated the expression of procathepsin L and cathepsin B in 29 cases of Kaposi's sarcoma (KS) using immunohistochemistry. The sample included 24 AIDS-associated KS and 5 non-AIDS-associated KS cases. Normal tissues such as epidermis, eccrine sweat glands, hair follicles, and blood vessels showed expression of both cathepsins. However, no expression of these enzymes was observed in the "angiomatous" and "fibroblastic" lesions of KS. These results suggested that KS lesions might have a benign autochthonous origin, such as hyperplasia.