Endocrine Abstracts

Paraganglioma syndromes (PGL) encompass a diverse group of rare neuroendocrine tumours that are characterised by hereditary predisposition and present unique diagnostic and management challenges. We performed an audit to assess the prevalence, presentation, testing, diagnosis, and treatment of these patients. We did a retrospective analysis of the genetic database and medical records of PGL patients diagnosed and managed at our hospital up till April 2023. A total of 119 cases were identified. 71% carried the SDHB mutation (PGL4), 18% carried SDHD (PGL1), 6% SDHC (PGL3) and 5% SDHA (PGL5) mutations. None were identified with SDHAF2 mutation (PGL2). All tumours presenting in 11 SDHD (PGL1) cases were head and neck tumours (HNPGLs), of which 31% were unilateral carotid body tumour (CBT), 9% bilateral CBT, 4% glomus jugulare tumour, and 4% skull base (SKB) tumour. Four cases were secretory with elevated plasma metadrenaline, plasma normetadrenaline and methoxytyramine. None of the 7 cases of SDHC (PGL3) had any tumours. Of the 84 cases of SDHB (PGL4), 8 had CBT, 5 had Pheochromocytoma-Paraganglioma (PPGL), 2 had SKB tumour, 2 had renal cell carcinoma and 1 had bladder tumour. 11% were secretory with high metanephrines. Of the 6 SDHA (PGL5) cases, 1 presented with pituitary macroadenoma and pheochromocytoma. 40 of the 119 cases were index cases and 79 family members. Penetrance by 60 years for developing PPGL/HNPGL was 58% in SDHB, 66% in SDHC and 74% in SDHD index cases. Penetrance in non-probands was 22.5% in SDHB, 25% in SDHC, 50% in SDHD. We offer screening and individualised treatment as per international guidelines. We measure plasma free or urinary fractionated metanephrines, MRI scan for imaging and for functional PGL we use [68Ga]-DOTA-SSA PET/CT. For children we start screening at 6-10 and 10-15 years for SDHB and SDHA/C/D mutation carriers, respectively.