Endocrine Abstracts

Case history: A 66-year-old man presented with a 1 month history of a productive cough, in the context of a 20 pack-year smoking history. CT chest revealed minor bronchiectasis and an incidental 3 cm right adrenal lesion. He was referred to the endocrine clinic for further evaluation. On questioning, he reported no symptoms suggestive of adrenal hormone hypersecretion and, aside from a short history (<1 month) of sweating episodes at night, he described no other constituti...

Background: Primary aldosteronism (PA) is responsible for 5-10% of all cases of HTN. The current gold standard test for determining the side of aldosterone hypersecretion is adrenal vein sampling (AVS). 11C-Metomidate PET/CT (METO-PET) has recently emerged as a potential non-invasive alternative to AVS. As 11C-Metomidate is concentrated within ‘hyperfunctioning’ nodules, METO-PET potentially not only identifies the side, but the exact site of al...

Background: Prolactinomas are the commonest hormone-secreting pituitary adenomas. First-line treatment is dopamine agonist (DA) therapy. However, side-effects are increasingly recognised, leading to an increasing consideration of transsphenoidal surgery (TSS) and/or radiotherapy. Co-registration of 11C-methionine Positron Emission Tomography (Met-PET) imaging with Spoiled Gradient Recalled Acquisition MRI (SPGR MRI), referred to in combination as Met-PET/MRI, can aid accurate ...

Acromegaly is a clinical manifestation of excessive peripheral growth hormone (GH) action. Most cases result from pituitary somatotroph adenomas displaying varying degrees of GH immunoreactivity. Occasionally, GH is cosecreted with a second hormone from adenomas containing mixed cell populations (e.g. somatolactotroph tumours). Coexistence of multiple discrete adenomas, identical or distinct in hormone secretion, is infrequent. In very rare cases, acromegaly results from neuro...

Background: Primary aldosteronism (PA) is now recognised to account for 5–10% of all cases of hypertension (and 20–25% of refractory hypertension). For patients with a demonstrable unilateral cause, adrenalectomy offers the potential for cure of PA, although resolution of hypertension occurs in only ~50% of patients. We have examined histological appearances and radiological features in patients with APAs undergoing adrenalectomy in an attempt to further our understa...

Background: Thyrotropinomas (TSHomas) are traditionally considered a rare, albeit important cause of thyrotoxicosis. Although early case series reported a predominance of invasive macroadenomas, emerging evidence suggests microadenomas are being increasingly diagnosed, and the clinical/biochemical phenotype appears to be more variable than previously suspected. We therefore performed detailed phenotyping of patients referred to our centre with a diagnosis of TSHoma over a 4-ye...

Background: BIPSS remains the gold standard for differentiating pituitary and ectopic sources in ACTH-dependent Cushing’s syndrome. A pituitary:peripheral ACTH ratio >2 in the basal state, and/or >3 following CRH stimulation, is considered indicative of pituitary Cushing’s, with a range of sensitivities and specificities cited in the literature. In addition, in Cushing’s disease a peak interpetrosal gradient of >1.4 has been reported to predict the s...

Sleep disordered breathing (SDB), including obstructive sleep apnoea (OSA), is associated with excessive daytime somnolence, and impacts significantly on quality of life in affected individuals. It also predisposes to premature cardiovascular (hypertension, congestive cardiac failure, myocardial infarction, sudden death, and stroke) and metabolic (diabetes mellitus and dyslipidaemia) dysfunction.SDB is a well-recognised complication of acromegaly. In mos...

Background: Thyrotropin secreting adenomas (TSHoma) are considered to be rare pituitary tumours. However, improvements in imaging techniques and greater use of more sensitive thyrotropin (TSH) assays has led to a recent increase in the detection rate of TSHomas and, specifically, the identification of more microadenomas. Surgery is considered the mainstay of treatment, however, primary medical therapy with somatostatin analogues is an emerging alternative therapeutic option.</...

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 <...