Essential Thrombocythemia Complicated by Occlusive Thrombosis of the Abdominal Aorta.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm of excessive platelet production complicated by thrombohemorrhagic events. Thrombosis typically occurs in small to medium vessels; thrombosis of large vessels is rare.

A 75-year-old woman with ET complicated by bilateral retinal vein occlusion was evaluated for fatigue, early satiety, and unintentional weight loss. Her hypertension was well controlled, and her chronic lower extremity claudication from peripheral artery disease was stable. She reported adherence to aspirin 81 mg and hydroxyurea 1000 mg daily, and her platelets (375 × 10⁹/L) were at goal. Bone marrow biopsy was consistent with ET without progression to myelofibrosis or leukemia. CT abdomen demonstrated complete occlusion of the infrarenal aorta, extending into the common iliac arteries, with reconstitution of flow distally via collaterals. The addition of clopidogrel, for platelet inhibition, and cilostazol, for claudication, caused symptom improvement without further thrombosis or bleeding.

There are few published reports of ET complicated by aortic thrombosis. To our knowledge, this is the first report of aortic thrombosis occurring in an ET patient with normal platelet count on antiplatelet and cytoreductive therapies. There is limited evidence to guide treatment, but medical management with triple antiplatelet therapy may be effective in selected patients.