FRI601 Unique Considerations For Workup And Management Of An 11 Year Old Male With Concern For A Neuroendocrine Tumor

Disclosure: N.C. Gunaratne: None. D. Deplewski: None. Background: Pheochromocytoma/paragangliomas are very rare in children. In patients who are undergoing work up for paragangliomas and pheochromocytomas, special considerations need to be made to distinguish neuroendocrine tumor findings from medication and other symptoms. Clinical Case: An 11 yo male with past medical history of migraines presented with new onset seizure, hypertension and tachycardia. Initial exam was remarkable for severe lower back pain, which eventually progressed to generalized pain. His tachycardia and hypertension were initially thought to be related to his pain, but were not improved with escalating pain and intermittent anti-hypertensive medications – leading to admission to the intensive care unit. He was started on lisinopril and metoprolol, but continued to have persistent tachycardia and hypertension.Initial work up included an echocardiogram revealing concentric left ventricular hypertrophy suggesting long-standing hypertension, MRI brain significant for Posterior Reversible Encephalopathy Syndrome, MRI abdomen and spine with no significant findings, and elevated urine metanephrines. Urine and serum catecholamines and serum metanephrines were also elevated, but not at levels typical of neuroendocrine tumors. Due to concern for possible pheochromocytoma/paraganglioma, patient was started on alpha-blocker phenoxybenzamine, and had marked improvement in hypertension. Patient was also started on scheduled gabapentin one day after initiation of phenoxybenzamine and noted to have some improvement in pain – making cause of acute improvement in blood pressure less clear. Patient underwent Ga-68 DOTATATE imaging that was significant for “mild to moderately increased activity within the left adrenal gland,” but no distinct lesion was appreciated on scan. After discussion with endocrine surgery, plan was made to monitor the patient in outpatient setting with serial plasma free metanephrines and chromogranin A while continuing phenoxybenzamine. Conclusion: Pheochromocytoma/paragangliomas are very rare in children. In patients who are undergoing work up for paragangliomas and pheochromocytomas, special considerations need to be made when patient has concomitant pain or is on beta-blockers. Ability to interpret urine/plasma metanephrines and catecholamine levels while on beta-blockers and other pharmacologic agents is difficult due to known iatrogenic alterations of these levels. Management for patients with elevated metanephrines without a localized neuroendocrine tumor can consist of pharmacologic intervention with alpha-blockers and close monitoring with serial labs. Presentation: Friday, June 16, 2023