A fatal case of heparin-induced thrombocytopenia and thrombosis.

Heparin induced thrombocytopenia (HIT) is a significant, potentially life-threatening immune-mediated adverse event that occurs several days after commencement of therapy with unfractionated or low-molecular weight heparin. We present a 51-year-old female treated with unfractionated heparin for acute deep venous thrombosis (DVT) and pulmonary embolism (PE). She developed extension of her thrombosis and was promptly diagnosed with heparin-induced thrombocytopenia and thrombosis (HITT). She did not, however, develop thrombocytopenia until 5 days after the extension of her thrombosis. The possible diagnosis of HITT is important for clinicians to keep in mind for all patients that are receiving any form of heparin, not only those patients who present with thrombocytopenia but also those with otherwise unexplainable thrombosis regardless of the platelet count.