MON-377 Hereditary Paraganglioma Pheochromocytoma Syndrome in the Setting of End Stage Renal Disease

Abstract

Pheochromocytomas and Paragangliomas represent rare catecholamine producing tumors of the adrenal gland or sympathetic/parasympathetic nervous system respectively. These can arise de novo or can result from genetically inherited mutations that predispose their origin. Overall these are rare tumors that can range from being asymptomatic to have symptoms related to excess catecholamines (including labile hypertension). While labile blood pressure is often associated with end stage renal disease (ESRD), pheochromocytoma/paragangliomas as cause of this are very rare with only 30 cases being reported in the literature. We report the case of a hereditary paraganglioma in a patient with ESRD. The patient is a 19 year old man with a history of ESRD secondary to hypoplastic kidneys and hypertension. He had initial presented to the hospital with shortness of breath in the setting of missing hemodialysis (HD). He received a session of HD in the emergency department without improvement and was placed on BIPAP. As part of his admission workup he had a CT of his chest which was negative for PE but did show a 5.3 by 3.5 by 4.7 cm left periaortic mass. Suspicion for possible paraganglioma was raised in the setting of difficult to control blood pressure along with his reported symptoms of palpitations and periodic sweats. Plasma metanephrines drawn after HD revealed an elevated normetanephrine of 28 nmol/L (<0.90 nmol/L) and plasma catecholamines were elevated with a norepinephrine of 17,928 pg/ml ( 70-750 pg/ml while supine or 200-1700 pg/ml while standing) and dopamine of 123 pg/ml (<30 pg/ml). He underwent metaiodobenzylguanidine (MIBG) scanning that showed abnormal radiotracer uptake in the left periaortic mass concerning for a paraganglioma. He was started on alpha-blockade and arrangements were made for surgery in several weeks time. While awaiting surgery genetic testing for hereditary paraganglioma pheochromocytoma syndrome returned positive for a variant mutation in SDHB. He underwent successful resection of his paraganglioma and was able to come off of his blood pressure medications. Postoperative testing showed normalization of his plasma metanephrines and catecholamines and arrangements were made for his siblings to undergo genetic testing. This case represents a relatively rare presentation of a paraganglioma in a patient with ESRD. The typical diagnostic workup for a paraganglioma can often not be pursued as 24 hour urine catecholamines can often not be collected as patients are often anuric/oliguric so plasma catecholamines must be pursued. Clinicians must be aware that those on HD can naturally have elevated catecholamines as a result of sympathetic nervous system activation from fluid shifting. Studies have shown that these values never exceed more than 3 times the upper limit of normal as a result of HD and values beyond that should raise suspicion for a paraganglioma or pheochromocytoma.