Endocrine Abstracts

Background: The enzyme succinate dehydrogenase (SDH) functions in the citric acid cycle and loss of function of this enzyme can lead to the development of phaeochromocytoma/paraganglioma (PPGL), gastrointestinal stromal tumour (GIST) and renal cell carcinoma. A germline mutation in one of the four genes (SDH-A/B/C/D) encoding the SDH complex is the most common mechanism of SDH inactivation causing SDH deficiency and is routinely screened for...

Case history: A 38-year-old man was referred with a 12-month history of recurrent bouts of transient hyponatraemia (serum sodium ranging from 115 to 125 mmol/l). Citalopram, which he was taking for depression, was discontinued, but the episodes continued.Initial investigations: Whilst symptomatic, and clinically euvolaemic, his biochemical profile was consistent with a syndrome of inappropriate antidiuresis (SIAD): sodium 124 mmol/l, potassium 4.5 mmol/l...

Although adrenal vein sampling (AVS) remains the gold-standard for distinguishing unilateral and bilateral disease in primary hyperaldosteronism (PHA), it is technically demanding and not always feasible. Metomidate (MTO), a potent inhibitor of CYP11B1 and CYP11B2, can be C11H3-labelled as a PET tracer (11C-MTO), and we have previously shown it to be an alternative to AVS for localising unilateral aldosterone-producing adenomas (APAs) (Burton <...

Section 1: Case history: A 38 year old female was identified as carrying a heterozygous pathogenic MEN1 variant (c.13404delG) through predictive testing, following a diagnosis of familial hyperparathyroidism.Section 2: Investigations: Routine screening for hyperparathyroidism and pituitary disease was negative. However, a CT thorax–abdomen–pelvis revealed a 41 mm pancreatic tail mass. Biopsy via endoscopic ultrasound confirmed a well-d...

Background: Endocrine Society guidelines classify macroprolactinomas as ‘resistant’ if there is failure to normalise prolactin, or to achieve radiological tumour shrinkage of >50%, on standard doses of dopamine agonist. In this context, escalation of treatment to maximal tolerable doses and/or referral for surgery is advised. However, we have recently observed several ‘discordant responders’, where tumour shrinkage lags significantly (>6 months) beh...

Nineteen cases of insulinoma were treated in this centre between 2003 and 2012 (12 female, 7 male, 5 associated with MEN-1). Of the cohort, 14 had their primary investigation and management here. All presented with symptoms consistent with hypoglycaemia and had a supervised fast demonstrating serum glucose <2.2 mmol/l with inappropriately normal/elevated insulin.11 of 14 patients proceeded to surgery. Two elderly patients declined further investigati...

Background: Primary aldosteronism (PA) is the leading, potentially reversible, cause of secondary hypertension. For most patients in whom surgery is being considered, adrenal vein sampling (AVS) is recommended to distinguish unilateral and bilateral causes. However, AVS remains technically challenging, and a significant proportion of patients are unable to progress to surgery because AVS is unavailable or unsuccessful. We have explored whether [11C]Metomidate PET/CT...