Endocrine Abstracts

Pheochromocytomas account for increased catecholamine secretion in about 90% of cases. Less than 5% of Less head and neck paragangliomas (PGs) secrete catecholamines. As in all extra-adrenal catecholamine secreting paraganglionomas (CSPs) they produce predominantly norepinephrine and little epinephrine secretion. About 25% of PGs are familial and have mutations involving RET,VHL, SDHB, SDHC or SDHD and other newly described genes.

We present two cases of carotid body tumours (CBT) with systemic manifestations and increased catecholamine secretion.

Case 1

A 44 year old gentleman presented with dizziness, headache, facial flushing and blackouts while coughing. He had no significant past medical history and he was not on any medications. There was no family history of note. He had elevated Plasma normetadrenaline (1736 pmol/L) and 3 methoxytyramine levels (290 pmol/L). The adrenal CT scan was normal. Examination of his neck revealed a painless 6 cm right neck swelling. MRI scan showed a 4.0×2.2×6.2 cm contrast enhancing lesion between the internal and external carotid artery. This neck lesion was MIBG, Octreotide avid and his adrenals were normal. Genetic tests confirmed that he had SDHB mutation. He has been managed with medical therapy so far and his symptoms have improved.

Case 2

A 43 year old lady presented with 6 month history of light headedness and pre-syncope usually when lying flat or on extension of her neck. Her mother had renal cell carcinoma. A duplex scan confirmed bilateral carotid body tumours measuring 3.2 (right side) and 1.6 cm (left side). 24 hour urine levels for metadrenaline (2.14 umol), normetadrenaline (5.21 umol) and 3 methoxytyramine (5.03 umol) were elevated. CT and FDG PET scan confirmed bilateral carotid body. Right CBT was MIBG avid and she had surgery after α and β blockade. Genetic tests confirmed that she had SDHD mutation. We will discuss the management of these tumours, particularly optimization of medical therapy prior to the surgery.