Unusual case report of malignant pheochromocytoma presenting with STEMI.

Background: Pheochromocytomas (PHEOs) are a group of tumours that leads to multiple symptoms and can induce hypercoagulability and promote thrombosis. Pheochromocytomas may also present without elevated serum and urinary markers. We aimed to provide tips and tricks for the diagnostic and therapeutic management of an unusual case of PHEOs. Case summary: Thirty-four-year-old woman with the unremarkable medical history presented with epigastric pain and dyspnoea. Electrocardiogram showed ST-segment elevation in the inferior limb leads. She underwent an emergency coronary angiogram, which showed a high thrombus burden in the distal right coronary artery. A subsequent echocardiogram demonstrated a 31 × 33 mm right atrial mass adhering to the inferior vena cava and abdominal computed tomography (CT) scan revealed a 113 × 85 mm necrotic mass in the left adrenal bed, with tumour thrombus extending proximally to the confluence of hepatic veins immediately inferior to the right atrium and distally to iliac vein bifurcation. Blood parameters, thrombophilia panel, vanillylmandelic acid, 5 hydroxy indole acetic acid, and homovanillic acid levels were normal. Tissue sampling confirmed the diagnosis of PHEOs. The surgical procedure was not planned due to the presence of metastatic foci on imaging, including positron emission tomography (PET)-CT. Anticoagulation with rivaroxaban and treatment with Discussion: The coexistence of arterial and venous thrombosis is extremely rare in patients with PHEOs. Multidisciplinary approaches are required for the care of such patients. Catecholamines likely contributed to the development of thrombosis in our patient. Early recognition of PHEOs is the key point to ameliorate clinical outcomes.