SUN-924 Functioning Abdominal Paraganglioma Presenting as Acute ST-Elevation Myocardial Infarction

Background: Functioning paraganglioma is a rare catecholamine-producing tumor that arises in the sympathetic nervous system. It usually presents with sustained or paroxysmal hypertension accompanied by episodes of its classic triad of headache, palpitation, and diaphoresis. However, a wide range of signs and symptoms may be present. We report an unusual manifestation as acute myocardial infarction, which accidentally diagnosed by the trigger response from metoclopramide injection. Case presentation A 66-year-old woman with medical history of well-control hypertension, dyslipidemia and type 2 diabetes mellitus for 8 years presented with typical angina pain for 1 hour. She denied history of chest pain or triad symptoms of pheochromocytoma/paraganglioma (PCC/PGL). Her physical examination was unremarkable except severe hypertension, 206/89 mmHg, and occasional sinus tachycardia. Acute inferior wall myocardial infarction was proposed by an electrocardiogram study, acute ST elevation in lead II, III and aVF, and highly elevated cardiac enzymes. Echocardiogram and coronary angiography showed preserved left ventricle function (LV ejection fraction 70%) without regional wall motion abnormality. No evidence of coronary artery disease was found. During the catheterization, the cardiologist raised the possibility of the presence of PCC/PGL from her fluctuating blood pressure, 73/42 to 206/113 mmHg, after 10-mg metoclopramide injection to control her vomiting. Computer tomography of the abdomen showed a lobulated heterogeneous enhancing left para-aortic mass with internal necrosis, 6.1x4.9x4.1 cm in size, abutting left anterolateral aortic wall and encasing celiac trunk, superior mesenteric artery, and left renal arterial wall. Her hormonal study showed 24-hour urine fractionated metanephrine/normetanephrine levels of 2,924 nmol (<1,777 nmol)/4,328 nmoL(< 3,279 nmol), respectively, and plasma free metanephrine/normetanephrine levels of 93.66 pg/mL (0-96.6 pg/mL)/233.61 pg/mL (0-163.05 pg/mL). She underwent surgical tumor removal with uneventful outcome and the pathology confirmed the diagnosis of functioning PGL. During 2-years follow-up, the patient remained asymptomatic and her hormonal and functioning imaging study showed no recurrence. The genetic testing for PCC/PGL panel was negative. Conclusion: We present an unusual manifestation of PCC/PGL as acute coronary syndrome. The clinician should remind this tumor as the differential diagnosis, especially in a patient with negative coronary angiogram.