Case presentations: Case 1: The index case is a 10 year old girl who presented episodic symptoms of feeling unwell, unexplained headache, seizure, vomiting and dehydration over a period of 8 months. She was subsequently found to have systemic hypertension which led to further investigations revealing raised plasma noradrenaline of 32 and 103.7 (NR 05 nmol/). US abdomen suggested bilateral pheochromocytoma but an MIBG showed unilateral left sided increased uptake. She underwent a successful laparoscopic adrenalectomy with clinical and biochemical remission.
Case 2: Cascade testing revealed a positive SDHB mutation in her 55 year old paternal uncle. He had been investigated by cardiology for intermittent chest pain, palpitations and sweating. Investigation showed persistently elevated plasma 3-Methoxytyramine (3-MT) level (561.6/796.5/540.5; NR 0180 pmol/l) and urine at 6.86/6.51/3.94 (NR 02.3 umol/24 hr. MRI head /neck /abdomen and MIBG were unremarkable, and CT chest showed indeterminate nodule. Subsequent 18F-FDG-PET showed an intensely PET avid lesion. He underwent surgical resection and histology confirmed an intra-thoracic paraganglioma.
Case 3: The 17 year old daughter of the above patient also had the SDHB mutation but was completely asymptomatic. She had mildly raised urinary metadrenaline at 3.04 (NR 02.7 umol/24 hr) and plasma metanephrine at 1539.4 (01180 pmol/l) but normal 3-MT levels. MRI thorax/abdomen was normal but 18F-FDG-PET showed an intensely PET avid paraganglioma between the caudate lobe of liver and inferior vena cava.
Discussion: These cases demonstrate paragangliomas can show no or minimally positive symptoms or biochemistry and imaging plays a key role in surveillance. Interestingly all three family members were positive for three different metabolites associated with SDHB mutation. These cases demonstrated very intense uptake on 18F-FDG-PET, highlighting that functional imaging plays an important role in this condition.
04 Dec 2017
UK and Ireland Neuroendocrine Tumour Society