Kaposi's sarcoma

A vascular tumor, that forms masses in the skin (usually purple in color), lymph nodes, or other organs. It is caused by Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8), gamma human herpesvirus, predominantly found in the immunosuppressed.

The virus is present in most patients of human immunodeficiency virus (HIV)-associated multicentric Castleman's disease, that is a lymphoproliferative disorder with a prominent microvasculature.

Cf. B-cell lymphoma, primary effusion lymphoma