Neoplastic angioendotheliosis--further evidence supporting a lymphoid origin.

Neoplastic angioendotheliosis is a rare condition, most commonly presenting with a bizarre neurological illness associated with multifocal cerebral infarction due to the occlusion of small blood vessels by neoplastic cells. The histogenesis of the malignant cells is controversial with previous suggestions of an endothelial, epithelial or lymphoid origin. We have studied a case immunohistologically using a panel of monoclonal and polyclonal antibodies recognizing a range of lymphoid, endothelial and epithelial antigens. The results indicate that the malignant cells were of B-lymphoid origin. We also report a second case in which a patient with a high grade B-cell non-Hodgkin's lymphoma developed multiple painful skin nodules which showed the histological features of neoplastic angioendotheliosis. These findings support the view that neoplastic angioendotheliosis is a lymphoma with a propensity to localize and proliferate in small blood vessels throughout the body.