SAT-311 Retroperitoneal Paraganglioma in a Patient Post-Fontan: The Association

Abstract

Background: Pheochromocytomas and paragangliomas (PHEO/PGL) are catecholamine producing tumors of the autonomous nervous system that arise from the chromaffin cells in the adrenal medulla or extra-adrenal paraganglionic tissue. About 40% of these tumors are associated with germline mutations of the VHL, RET, NF1, SDHA, SDHB, SDHC, SDHD etc.(1). However, there are reports of chronic hypoxemia triggering the development of such tumors, especially in patients with congenital cyanotic heart disease (CCHD). PHEO/PGL in association with a CCHD was first reported in 5 cases in 1964(2). The youngest reports of this co-occurrence has been in two 13 year old male patients post-Fontan procedure, that presented about 10 years after this intervention(3, 4). Studies on patients with CCHD that developed PHEO/PGL, showed that patients were diagnosed at a median age of 24-31years, with a mean oxygen saturation of ~87% at diagnosis and a cyanosis duration of 6 - 25 years (4, 5). Case: We report a 12 year old female with a history of hypoplastic left heart, post lateral tunnel non-fenestrated Fontan procedure with mitral and tricuspid valvuloplasty performed at 4 years of age. Her resting oxygen saturation at presentation was 86-92%. She presented with frequent episodes of sweating, anxiety, chest pain and sustained hypertension (~200/90 mm Hg) refractory to anti-hypertensives, for a few months. A 24-hr urine collection showed a normetanephrine level of 5125mcg (ref: 67 - 503 mcg/24hr) with a plasma normetanephrine level of 37.8nmol/L (ref: 0 - 0.89nmol/L). No germ-line mutations were identified in the genes commonly associated with PHEO/PGL (MAX, NF1, RET, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127, VHL). CT scan revealed a left upper quadrant abdominal mass which on surgical resection was noted to be a para-aortic mass. Cytology confirmed a paraganglioma tumor. Conclusion: PHEO/PGL are rare entities in the pediatric population; however, their incidence is significantly higher among patients with CCHD. Though, most patients present during adulthood with PHEO/PGL, some may present earlier, and those caring for CCHD patients must be mindful of this complication.