blue rubber bleb nevus [OFr, blou, blue; + ME, rubben, to scrape; + ME, bleb, blob; + L, naevus, mole] , a type of congenital nevus, transmitted as an autosomal-dominant trait, characterized by blue hemangiomas with soft elevated nipple-like centers, found on the skin surface, in the GI tract, and sometimes on mucous membranes; it may be accompanied by pain, regional hyperhidrosis, or GI bleeding.