Endocrine Abstracts

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: 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 <...

Background: Hyperthyroxinaemia with non-suppressed TSH, due to resistance to thyroid hormone (RTH) or TSH-secreting pituitary tumour (TSHoma), can be difficult to diagnose, particularly with coincident autoimmune thyroid disease (AITD).Methods: To determine presentation patterns of AITD coincident with RTH or TSHoma, we analysed our cohort of cases with dual diagnoses.Results: Nine patients with RTH had AITD. Six had Graves’ d...

Case Report: A 49-year-old man presented with a two-year history of thyrotoxic symptoms for which he had been investigated on several occasions. He had a past medical history of dilated cardiomyopathy, which had been attributed to excess alcohol consumption, and had also suffered episodes of non-sustained ventricular tachycardia. His family history was strongly positive for autoimmune thyroid disease. Eventually, he was found to have an elevated fT4 (53 pmol/L, RR 12–22) ...

Introduction: Achieving optimal levothyroxine replacement is more difficult in TSH deficiency compared to primary hypothyroidism because of the inability to be guided by TSH. A combination of clinical symptoms and free thyroxine levels (fT4) are typically used to monitor replacement. We reviewed adequacy of levothyroxine replacement in our patients with pituitary disease, and compared with fT4 levels in patients with primary thyroid disease.<p class="...

Background: Acromegaly is associated with significant excess morbidity and mortality. Surgery and radiotherapy (including radiosurgery) aim to reduce the burden of growth hormone excess while preserving normal pituitary function, but their effective deployment is dependent on high quality imaging that allows accurate localization of site(s) of active de novo or residual/recurrent disease. Despite the existence of several comprehensive guidelines on the managem...