Triple-Negative Essential Thrombocythemia Complicated by Thrombosis and Acquired von Willebrand Disease in a Young Man.

BACKGROUND Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm (MPN) characterized by sustained thrombocytosis in peripheral blood. Patients typically have gene mutations like JAK2V617F, CALR, and MPLW515L/K. This report describes a young man with ET without any of the above mutations who had paradoxical bleeding due to acquired Von-Willebrand disease. CASE REPORT A young man with a medical history of thrombocytosis on aspirin presented with acute chest pain and was found to have had a myocardial infarction. Emergency cardiac catheterization revealed a thrombotic occlusion of the left anterior descending (LAD) artery and the right posteriolateral system, with an ejection fraction of 25%. He underwent thrombectomy and balloon angioplasty with LAD stenting, and an Impella 2.5 was inserted due to severe left ventricular dysfunction with akinesia. Aspirin and ticagrelor were administered, but the patient later experienced postoperative bleeding from the site of the Impella device. The bleeding was attributed to acquired Von-Willebrand disease secondary to ET. Emergency plateletpheresis was recommended. Further workup demonstrated that he was triple-negative for JAK2, MPL, and CALR gene mutations. CONCLUSIONS The paradoxical bleeding resulting from acquired Von-Willebrand disease was likely an entirely separate entity from the hyper-thrombotic state expected from ET. Careful assessment of clinical symptoms and laboratory markers, in addition to a high degree of suspicion, are needed to diagnose acquired Von-Willebrand disease as a complication of ET.