What is Kasabach-Merritt phenomenon (KMP)?
Kasabach-Merritt phenomenon (KMP) is a complication in which certain vascular tumors trap and destroy platelets. It can be a serious complication because platelets help form blood clots to stop bleeding and patients with KMP are at increased risk of bleeding. KMP may develop in patients with vascular tumors because the tumors reach a certain size or if there is early infection or inflammation.
Platelet transfusions can be given to stop significant bleeding or to prevent bleeding during necessary procedures. Otherwise, platelet transfusion should not be given, as they lead to tumor enlargement when new platelets are trapped in the tumor. Platelet counts and KMP improve during therapy for the tumor itself. Tufted angioma is a mild vascular tumor that is rarely complicated by KMP and is likely a mild variant of Kapisoform hemangioendothelioma (KHE). As most cases of KMP involve the tumor KHE, please see KHE for more information.