Waljit Dhillo

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.

Clinical outcomes in patients with nonfunctioning pituitary adenomas managed conservatively

The natural history and the optimum management of patients with nonfunctioning pituitary adenomas (NFPAs) are unclear.

A young fit man presenting to the emergency department with a painful neck due to a thyroid abscess

### Learning Point for CliniciansnnThis case exemplifies the need to consider less common diagnoses if a patient’s presentation is non-classical, such as in our patient who had an erythematous neck, unilateral thyroid lobe enlargement and grossly elevated white cell count and C-reactive protein (CRP) that would not be expected to occur with viral thyroiditis.nnA 38-year-old Caucasian man presented to our emergency department with a week’s history of sore throat, dysphagia, neck swelling and fever. One month prior, he experienced a respiratory tract infection, for which he had not sought medical advice and which had resolved without antibiotics. He had no history of trauma or procedures involving the neck. He had no notable past medical or family history. He was a non-smoker and drank 15 U of alcohol per week. On examination, he was a young fit man, slightly sweaty and flushed but otherwise looked …

Plasma gastrin:somatostatin ratio is decreased in gastrinomas

Introduction Fasting gastrin alone is inadequate for diagnosis of gastrinoma because hypergastrinemia occurs in a number of non-gastrinoma conditions, including atrophic gastritis. Confirmation of diagnosis requires more invasive investigations to demonstrate low gastric pH. The density of somatostatin secreting D-cells and gastrin secreting G-cells is dependent on gastric pH. A low gastric pH is associated with a relative increase in D-cell density, resulting in a decrease in G-cell:D-cell ratio. We compared plasma somatostatin levels and the plasma gastrin:somatostatin ratios in patients with achlorhydria secondary to atrophic gastritis and in patients with gastrinoma. We also compared chromogranin A (CgA) levels in the two groups. Methods Plasma gastrin, somatostatin and CgA were measured in 21 patients with gastrinomas and 23 patients with atrophic gastritis referred to the Supra regional Assay and Advisory Service Laboratory at our centre. Results There was no significant difference between plasma gastrin in patients with gastrinomas and atrophic gastritis. Plasma somatostatin was significantly higher in patients with gastrinomas compared to patients with atrophic gastritis (p<0.005). Gastrinoma patients had significantly lower plasma gastrin:somatostatin ratios compared to those with atrophic gastritis (p<0.001). Patients with gastrinomas had significantly higher plasma Cg A compared to patients with atrophic gastritis (p<0.005). No patients with atrophic gastritis had Cg A levels greater than100 pmol/L. The combination of plasma Cg A and plasma gastrin:somatostatin ratio has a predictive power of 76% and an area under ROC curve of 0.87. Conclusion The plasma gastrin:somatostatin ratio and measurement of plasma Cg A may be helpful in planning the diagnostic work-up for patients with raised fasting gastrin levels. Combining these biochemical tests could allow correct identification of gastrinoma patients requiring further assessment and significantly reduce unnecessary investigation of gastric pH in non-gastrinoma patients.

The secretin test can be used to diagnose a gastrinoma even in patients who cannot stop proton pump inhibitors.

A 3 year retrospective audit of chromogranin results in a tertiary referral centre: Is Chromogranin B measurement necessary? P.J. Monaghan, D. Darby, J. Valle, W. Mansoor, P.J. Trainer Department of Clinical Biochemistry, The Christie NHS Foundation Trust, Manchester, UK Department of Medical Oncology, The Christie NHS Foundation Trust, Manchester, UK Department of Endocrinology, The Christie NHS Foundation Trust, Manchester, UK