Endocrine Abstracts

Paragangliomas are rare tumours that arise from extra-adrenal chromaffin cells within the sympathetic paraganglionic axis. While neoplasms of the adrenal medulla, (phaeochromocytomas) are normally characterized by catecholamine (CA) hypersecretion, paragangliomas can be nonfunctional. We report our findings from 5 patients (4 males, 1 female) with paragangliomas. In 4 out of 5 patients the initial presentation was related to the space-occupying effect of the tumour. Episodic symptoms consistent with excess CA secretion was the predominant presenting feature only in one patient although 4 patients had hypertension. Four of the 5 patients had biopsies before a potential source of excessive CA secretion was suspected; in 3 patients undergoing biopsy a surge in blood pressure during the procedure was noted. Localization studies using CT and MRI was positive in all 5 patients while [¹²³I] MIBG was negative in the 3 patients. Levels of plasma or urinary CA and metadrenalines (HPLC with electrochemical detection) measured preoperatively were normal on multiple samples in 4 patients with only slightly raised urinary normetadrenaline in 1 patient. All hypertensive patients (including those with normal CA) were alpha and beta blocked before surgery. There were no perioperative complications and BP was stable during surgery. In two patients antihypertensive therapy has either been withdrawn or reduced postoperatively, with good BP control. Adrenergic blockade before surgery may be appropriate in hypertensive patients with non-functioning paragangliomas.