Fatal bleeding due to a heparin-like anticoagulant in a 37-year-old woman suffering from systemic mastocytosis.

A 37-year-old female patient with systemic mastocytosis who was admitted with severe unexplained bleeding symptoms is studied. Laboratory procedures established the diagnosis of a patient-derived-heparin-like anticoagulant as a very rare hemostatic abnormality predisposing to bleeding. The patient died from refractory disease despite therapy with protamine, initiation of chemotherapy, and supportive measures. The case illustrates the clinical presentation and diagnosis of heparin-like anticoagulants. Etiology, pathophysiology, and therapeutic options are discussed.