Endocrine Abstracts

Paragangliomas are rare neuroendrocrine tumours arising from extra-adrenal paraganglia of the autonomic nervous system and excess catecholamine secretion is associated with higher cardiovascular morbidity and mortality. We present the case of a 56-year old male referred to our outpatient clinic with symptoms of sympathetic-hyperactivity, including excessive sweating, palpitations and diastolic hypertension (140/100 mmHg). He had undergone bilateral thoracotomy and laparotomy on separate occasions in Poland many years ago to remove paragangliomas in the head, neck and abdomen. He also reported a strong family history of paraganglioma/phaeochromocytoma type 1 (PPGL-1) in his father, paternal grandfather, brother, sister and aunt. Polish medical reports document a mutation in the SDHD gene consistent with high genetic penetrance, however there had been a loss to follow up from routine surveillance. Current medications included doxazosin 4 mg daily. 24-hour urinary catecholamines revealed: Normetadrenaline 14304 nmol/24 hr (0–3300 nmol/24 hr), Metadrenaline 132 nmol/24 hr (0–1200 nmol/24 hr), 3-Methoxytyramine 979 nmol/24 hr (0–2500 nmol/24 hr). CT-imaging showed a well defined retroperitonal aortocaval mass 4.4 cm×4.5 cm at the level of L2, displacing the aorta and IVC laterally. A left partially obstructing ureteric calculus was also seen. Due to significant biochemical activity of the suspected retroperitoneal PPGL, he was commenced on alpha-blockade with Phenoxybenzamine 10 mg 3x/day prior to propranolol 40 mg twice daily. Further imaging is presented including MRI head/neck and ¹²³I-MIBG scintigraphy and the patient was referred to the local Endocrine MDT in view of complete surgical resection and histopathological analysis. Genetic testing is also presented for MEN and SDH subtypes. This case highlights the importance of biochemical evaluation as part of routine follow-up in patients with known PPGL to detect recurrent disease, for example retroperitoneal paragangliomas. It also highlights the importance of follow up of previously treated PPGL in the context of genetic syndromes for example SDH subunit mutations, which may result in a higher level of recurrent or metastatic disease.