Emma Hatfield

Adrenal venous sampling as a diagnostic procedure for primary hyperaldosteronism: experience from a tertiary referral centre

CONTEXTAdrenal vein sampling (AVS) is recommended in all patients with hyperaldos-teronism to whom surgery would be offered if the results indicated unilateral hypersecretion.OBJECTIVETo assess the performance of AVS against radiological findings and to evaluate the Endocrine Society’s Practice Guidelines for diagnostic cut-offs.PATIENTSRetrospective study of 41 patients with hyperaldosteronism who underwent both AVS and computed tomography (CT) imaging.RESULTSCT and AVS results were concordant in 73.7%. Unilateral lesions on CT had a greater positive predictive value (85%) than non-unilateral lesions (50%). In patients with subsequently confirmed adrenal adenomas, a lateralisation ratio >2 when comparing cortisol-corrected aldosterone ratios from the affected versus unaffected side was 100% sensitive. Patients who were managed surgically experienced significant reductions in blood pressure and medication burden and 46% were cured.CONCLUSIONSAVS is important in establishing unilateral or bilateral adrenal secretion of aldosterone in patients with primary hyperaldosteronism. However, it may not be essential for the work-up in patients below the age of 40, in whom adrenal incidentalomas adrenal incidentalomas are known to be rarer, and a unilateral lesion on CT therefore has a greater positive predictive value.

A legacy of tinnitus: multiple head and neck paragangliomas

We describe the case of a patient who presented with a right-sided glomus jugulare tumor and bilateral glomus vagale tumors. These proved to be nonmalignant paragangliomas on histopathological analysis. Genetic analysis revealed a germline heterozygous missense mutation (Pro81Leu) in the succinate dehydrogenase subunit D (SDHD) gene. We discuss the clinical presentations of the familial paraganglioma syndrome type 1, which is caused by mutations in SDHD, and the implications for the clinical diagnosis and care of such patients.

Interpretation of Serum Gonadotropin Levels in Hyperprolactinaemia

Background/Aims: Hyperprolactinaemia is a common cause of amenorrhoea due to hypogonadotropic hypogonadism. Prolactin is hypothesised to impede the reproductive axis through an inhibitory action at the hypothalamus. However, limited data exist to aid the interpretation of serum gonadotropins in the context of hyperprolactinaemia. Methods: Serum gonadotropin values were reviewed in 243 patients with elevated serum monomeric prolactin due to discrete aetiologies at a tertiary reproductive endocrine centre between 2012 and 2015. The cause of hyperprolactinaemia was categorised by an experienced endocrinologist/pituitary multidisciplinary team, unless superseded by histology. The most frequently encountered diagnoses were microprolactinoma (n = 88), macroprolactinoma (n = 46), non-functioning pituitary adenoma (NFPA) (n = 72), drug-induced hyperprolactinaemia (n = 22) and polycystic ovarian syndrome (PCOS) (n = 15). Results: In patients with prolactinoma and modestly raised serum prolactin levels (< 4,000 mU/L), increasingly FSH-predominant gonadotropin values were observed with rising prolactin level, consistent with a progressive reduction in hypothalamic gonadotropin-releasing hormone (GnRH) pulsatility. Patients with prolactinoma and higher prolactin values (> 4,000 mU/L) were more likely to have a reduction in serum levels of both FSH and LH, consistent with direct pituitary gonadotrope dysfunction. Patients with macroadenoma and extremes of serum gonadotropin values (either serum FSH or LH > 8 IU/L) were more likely to have NFPA than prolactinoma. Patients with PCOS and hyperprolactinaemia had LH-predominant secretion in keeping with increased GnRH pulsatility despite a raised prolactin level. Conclusion: The pattern of gonadotropin secretion in patients with hyperprolactinaemia reflects the underlying aetiology.

Severe hypercalcaemia in sarcoidosis: Is Vitamin D replacement safe?

• We report the case of a 66-year-old lady, who presented with a oneweek history of general weakness, drowsiness, nausea and confusion. • 6 weeks prior to presentation, she underwent right-sided intramedullary nail insertion for a traumatic femur fracture, whilst abroad. • Her past medical history includes stage IV pulmonary sarcoidosis, pulmonary hypertension and vitamin D deficiency. • Immediately post-operatively, she was started on calcium and vitamin D supplement including calcitriol (0.25 μg daily) and cholecalciferol (60,000 IU twice weekly). • On examination, she was clinically dehydrated with a blood pressure of 105/52 and sinus tachycardia of 110 beats per minute. She had bibasal crepitations on chest auscultation. Examination of neurological and GI systems was unremarkable. • Initial investigations revealed adjusted calcium of 5.35 mmol/L (NR 2.2-2.6), Phosphate 1.33 mmol/L (NR 0.8-1.5), creatinine 342 μmol/L (baseline 70 μmol/L), Urea 17.2mmol/L, PTH 1.2 pmol/L (NR 1.1-6.8). ECG showed sinus tachycardia with a cQT of 480 msec. Four months prior to presentation, 25 hydroxy-vitamin D (25(OH)D) level was 24.6 nmol/L (NR 70-150). • Her hypercalcaemia was felt to be secondary due to Vitamin D toxicity on the background of sarcoidosis. She was admitted to HDU, where she was treated with aggressive fluid resuscitation, increased dose of glucocorticoids, Calcitonin and diuretics, with subsequent clinical and biochemical improvement (Chart 1). • The result of 25(OH)D level came back raised at 390 nmol/L. DISCUSSION