A Rare Occurrence of Simultaneous Venous and Arterial Thromboembolic Events - Lower Limb Deep Venous Thrombosis and Pulmonary Thromboembolism as Initial Presentation in Acute Promyelocytic Leukemia

Aortic Thrombus Extending to Left Subclavian in a Patient With Diffuse Venous Thromboembolism on Aromatase Inhibitor Therapy

Concomitant arterial and venous thrombosis is an infrequent event often associated with malignancy, hyperhomocysteinemia, and thrombophilic conditions. Some overlapping pathophysiology mechanisms suggest an association between arterial and venous thrombosis. It is reported that thrombosis in the arterial and venous systems develops through distinct mechanisms affecting inflammatory and oxidative pathways. Recently, the aromatase inhibitors have moved to the forefront of adjuvant hormonal therapy, however, the adverse effects of these agents are not yet fully understood. It is generally accepted that tamoxifen, but not aromatase inhibitors, is associated with an increased risk of thrombosis in women with breast cancer. Here, we report an unusual case of an 87-year-old female on anastrozole therapy with aortic thrombus extending into the left subclavian artery with associated diffuse venous thromboembolism (VTE). An 87-year-old-female with a history of breast cancer in remission, obesity, hypertension, and dyslipidemia presented to the emergency department with new onset of left arm weakness and tingling sensation. Vital signs showed respiratory rate of 20 per minute, oxygen saturation of 95% on 3 L of oxygen via nasal cannula, blood pressure of 150/79 mmHg, and pulse 81 beats per minute. Computed tomography angiography (CTA) neck showed an aortic thrombus extending into the left subclavian artery and bilateral pulmonary emboli (PE). Doppler ultrasound of the lower extremities showed a deep venous thrombosis (DVT) in the left lower extremity. Echocardiography showed no patent foramen ovale. She was started on continuous heparin infusion and subsequently transitioned to an oral anticoagulation medication upon discharge. Symptomatic ischemic lesions of the upper extremity due to thrombosis of the subclavian artery are extremely rare, occurring in less than one percent of the population. While this patient had a history of early-stage breast cancer, she was on adjuvant anastrozole therapy with no evidence of recurrence or further tumor burden as per her outpatient oncologist, who also followed her during her hospital stay. She also had no prior history of thromboembolic disease or clotting disorders. Her only risk factors appear to be her age and her obesity (with a BMI over 30). Nevertheless, the extent of thromboembolism seen in this patient is greater than that might be expected with these factors. This case highlights a concomitant rarity of arterial and venous thrombosis. Also, there are not enough studies on anastrozole effect on thromboembolism. Given these risk factors, we recommend a high degree of suspicion for VTE in patients who are on anastrozole therapy.

A case of acute myelogenous leukemia characterized by arterial and venous thrombosis

Acute myelogenous leukemia (AML) is a malignant disease of the hematopoietic system, characterized by features of bone marrow insufficiency and organ infiltration by leukemic cells. Venous thrombosis in AML patients is uncommon, compared to bleeding; therefore in patients with AML, simultaneous occurrence of venous and arterial thrombosis is a rather rare presentation. We reported an unusual case of anti-phospholipid antibody syndrome secondary to AML characterized by venous and arterial thrombosis. A 70-year-old man with deep venous thrombosis (DVT) of the left leg confirmed by Doppler was seen in our clinic. During treatment with a Vitamin K antagonist (3 mg daily of Warfarin) and a low molecular weight heparin (LMWH), he developed an acute pulmonary embolism and an acute inferior wall ST elevation myocardial infarction (STEMI), a result of right coronary artery embolism. His full blood count showed leukocytosis and thrombocytopenia. Lupus anticoagulant and anti-cardiolipin antibodies were positive. A bone marrow aspirate test showed results consistent with AML (FAB class M1). A diagnosis of antiphospholipid antibody syndrome secondary to AML characterized by coronary artery embolism, pulmonary embolism and left leg DVT was eventually established. He received anticoagulation with a low dose of warfarin after refusing chemotherapy. He however died of cerebral hemorrhage despite the fact that the INR was in the normal therapeutic range. It is challenging to anticoagulated AML patients complicated by multiple vascular thromboses and thrombocytopenia.