MON-LB041 Pheochromocytoma - Illusive Myriad of Symptoms

Abstract

Background: Pheochromocytoma is a rare neuroendocrine neoplasm arising from the adrenal medullary chromaffin cells. It contributes to 80-85% of catecholamine secreting tumors. The annual incidence of pheochromocytoma is 0.8 cases per 100,000 person-years. It can be both sporadic or familial. The classic triad of headache, palpitations and diaphoresis is seen in only 4% of cases. Rare presentations include cardiomyopathy, stroke, diabetes mellitus, ventricular arrhythmias and myocardial infarction. Our patient presented concurrently with dilated cardiomyopathy, hypertensive emergency and new-onset diabetes mellitus (DM) followed by ischemic stroke within a week. Heart failure can present as takotsubo or dilated cardiomyopathy with an incidence of 10%. The underlying pathophysiology is catecholamine mediated myocardial stunning, diffuse coronary vasospasm, microvasculature dysfunction and fibrosis. DM is seen in 23% of pheochromocytoma and is due to catecholamine-induced impaired glucose tolerance, and insulin resistance. Cerebral ischemia has an incidence of 3%, and is secondary to severe hypertension and cerebral vasospasm. Clinical Case: A 47-year-old African American woman presented with a 1-week duration of worsening dyspnea, orthopnea, dizziness, and palpitations. Past medical history includes HTN, non-ischemic cardiomyopathy on carvedilol and pravastatin. Physical exam: BP 182/119, HR 120, mild pulmonary crackles. Labs: proBNP 3533 (1-150 pg/ml), HbA1c 13.1%. Echocardiogram: moderate global hypokinesis with left ventricle ejection fraction (LVEF) of 30-35%. On imaging, CT of chest revealed an incidental finding of 4.7 cm right adrenal adenoma. MRI abdomen confirmed heterogeneously enhancing 4.3 cm right adrenal mass. Further testing showed high plasma catecholamines of 9963 (242-1125 pg/ml), 24-hour urine catecholamines of 2125 (50-100 mcg), thus confirming the diagnosis of pheochromocytoma. Further, her clinical course was complicated by left-sided weakness. MRI brain reported an acute infarct in right corona radiata. Pre-operative blockade was done with phenoxybenzamine and metoprolol. Subsequently, she underwent right adrenalectomy and tissue diagnosis confirmed pheochromocytoma. On follow up visit, her symptoms resolved. Also noted normalized catecholamine levels, HbA1c of 5.4% and LVEF of 40- 45%. Conclusion: Pheochromocytoma can rarely present with multi-organ failure. It warrants a high index of suspicion in non-ischemic cardiomyopathy. As per recent Mayo Clinic criteria, diagnosis of takotsubo cardiomyopathy mandates ruling out pheochromocytoma. As seen in our patient, it is a reversible cause of left ventricular dysfunction, focal weakness and DM. Based on our knowledge, this is the only contingently diagnosed pheochromocytoma with varied clinical presentations. It has been aptly described as “The Great Masquerader”.