An 82-year-old patient with untreated chronic lymphatic leukaemia know
n for 6 years developed large livid red plaques with central blisters
and subsequent ulceration of the lower legs, Reactive angioendotheliom
atosis was diagnosed based on histological immunohistological and elec
tronmicroscopic examination, since proliferating endothelial cells wit
h intravascular fibrin thrombi were identified. When the leukaemia was
treated the skin eruption healed completely.