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Traditionally it is recommended that hyperthyroid patients should be made euthyroid prior to thyroidectomy. However, several small observational studies have reported no increase in adverse events when hyperthyroid patients undergo thyroidectomy. The aim of this study was to assess outcomes following total thyroidectomy in patients who were biochemically hyperthyroid at the time of surgery compared to those who were euthyroid. One hundred and fifty-one eligible patients undergoing thyroidectomy for hyperthyroidism between January 2012 and February 2016 were identified, of whom 57 were hyperthyroid on perioperative blood tests and 94 were euthyroid (comparison group). Primary outcomes were 30-day mortality, increased length of postoperative hospital stay and intraoperative signs consistent with thyrotoxicosis (e.g. heart rate >100 per minute, systolic blood pressure >180 or <60 mmHg, or temperature >38°C). Secondary outcomes were intraoperative beta-blocker use and level of care required postoperatively. Thirty-day mortality was zero. The only significant difference between the two groups was a higher use of intraoperative beta-blockers amongst hyperthyroid patients (28.1% versus 8.5%, P=0.002). Our findings suggest that thyroidectomy for mild to moderate biochemical hyperthyroidism performed by an experienced thyroid surgeon and anaesthetist, is associated with increased intraoperative beta-blocker use but no statistical difference in mortality, length of postoperative stay or intraoperative signs consistent with thyrotoxicosis. While we still recommend attempting to achieve a euthyroid state whenever possible prior to thyroid surgery, mild to moderate degrees of residual biochemical hyperthyroidism when appropriately managed may not be associated with an increase in adverse outcomes.

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OBJECTIVES: Anaemia and thyrotoxicosis are both relatively common. It is unclear whether thyrotoxicosis results in anaemia in the absence of other causes. The aim of this study was to determine the prevalence and characteristics of anaemia in patients with thyrotoxicosis. DESIGN: A prospective cohort study of patients with thyrotoxicosis. PATIENTS: 353 patients referred to a regional endocrinology centre in New Zealand from March 2013 to November 2014 for new-onset thyrotoxicosis. MEASUREMENTS: Detailed assessment including thyroid function tests, full blood count, inflammatory markers, haematological parameters and coeliac serology. Anaemia was defined as a haemoglobin value <115 g/L (woman) or <130 g/L (men). RESULTS: Anaemia was present in 31 (8.7%) patients at diagnosis. Of these, pre-existing anaemia was present in 10, and a further 11 had one or more identifiable underlying cause(s) for the anaemia. Only 10 patients (2.8% of the entire cohort) had anaemia not clearly attributable to another cause. Median free thyroid hormone levels were higher in those with anaemia of unknown cause compared to patients with thyrotoxicosis alone. The median duration of anaemia was shorter in patients with thyrotoxicosis-associated anaemia compared to those with anaemia due to an underlying cause (1 vs 6 months, P = .001). In all patients with thyrotoxicosis-associated anaemia, the anaemia resolved, either prior to, or on becoming euthyroid. CONCLUSION: Anaemia coexisting with thyrotoxicosis is less common than previously reported and is mild and transient. Patients with thyrotoxicosis and significant anaemia should be investigated for other potential causes, particularly when anaemia persists.

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Cushing's syndrome (CS) due to ectopic adrenocorticotrophic hormone (ACTH) is associated with a variety of tumours most of which arise in the thorax or abdomen. Prostate carcinoma is a rare but important cause of rapidly progressive CS. To report a case of severe CS due to ACTH production from prostate neuroendocrine carcinoma and summarise previous published cases. A 71-year-old male presented with profound hypokalaemia, oedema and new onset hypertension. The patient reported two weeks of weight gain, muscle weakness, labile mood and insomnia. CS due to ectopic ACTH production was confirmed with failure to suppress cortisol levels following low- and high-dose dexamethasone suppression tests in the presence of a markedly elevated ACTH and a normal pituitary MRI. Computed tomography demonstrated an enlarged prostate with features of malignancy, confirmed by MRI. Subsequent prostatic biopsy confirmed neuroendocrine carcinoma of small cell type and conventional adenocarcinoma of the prostate. Adrenal steroidogenesis blockade was commenced using ketoconazole and metyrapone. Complete biochemical control of CS and evidence of disease regression on imaging occurred after four cycles of chemotherapy with carboplatin and etoposide. By the sixth cycle, the patient demonstrated radiological progression followed by recurrence of CS and died nine months after initial presentation. Prostate neuroendocrine carcinoma is a rare cause of CS that can be rapidly fatal, and early aggressive treatment of the CS is important. In CS where the cause of EAS is unable to be identified, a pelvic source should be considered and imaging of the pelvis carefully reviewed.

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The synthetic glucocorticoid dexamethasone is administered to many patients receiving a general anaesthetic to reduce the risk of postoperative nausea and vomiting. Dexamethasone is known to suppress the hypothalamic-pituitary-adrenal axis; however, the duration of this suppression following the standard anti-emetic intravenous dose of 4 to 8 mg used with anaesthesia is unknown. A randomised controlled double-blind crossover trial assessing the effects of 8 mg intravenous dexamethasone versus saline control was performed in ten healthy male volunteers. The adrenal, thyroid and gonadal axes and glucose levels were assessed over a four-day period after dexamethasone administration. All participants had normal baseline hypothalamic-pituitary-adrenal axis function. No difference in cortisol levels was demonstrated at four or eight hours after dexamethasone administration compared with placebo. At 24 hours post dexamethasone, the cortisol had dropped to less than 5% of baseline and returned to normal during the subsequent day. Increased plasma glucose levels were also observed in the dexamethasone group as compared with placebo. A dose of 8 mg of dexamethasone results in significant suppression of the hypothalamic-pituitary-adrenal axis and elevated plasma glucose levels. The cortisol suppression is maximal at approximately 24 hours post dose.

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Phaeochromocytomas and paragangliomas are rare neuroendocrine tumours that arise from the adrenal glands or paraganglia (paragangliomas) within the abdomen, thorax and neck. Although it was originally suggested that approximately 10% of these tumours were inherited, it is now recognised that up to approximately 30% of these tumours are associated with a germline mutation in one of the phaeochromocytoma/paraganglioma susceptibility genes. Of the 12 currently known genes predisposing to these tumours, the TMEM127 gene is one of the more recently identified and appears to be present in approximately 2% of apparently sporadic phaeochromocytomas. We report a 33-year-old man who presented with an apparently sporadic adrenal phaeochromocytoma and was identified as carrying a novel TMEM127 germline mutation, p.Gln139X. Patients harbouring a germline TMEM127 mutation most commonly present with an apparently sporadic solitary adrenal phaeochromocytoma. Testing patients who present with a phaeochromocytoma or paraganglioma for an underlying germline mutation needs to be considered in all patients due to implications for family members, but a strategy based on clinical and immunohistochemical findings would be prudent to limit costs.

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Multiple endocrine neoplasia type 2a results from an activating germline mutation in the RET proto-oncogene. Carriers of a RET mutation are at risk of medullary thyroid carcinoma, pheochromocytoma, and primary hyperparathyroidism. Most individuals with multiple endocrine neoplasia type 2a eventually develop medullary thyroid carcinoma and as there is a strong genotype-phenotype correlation, guidelines have been established as to the age recommended for prophylactic thyroidectomy. However for rare mutations in the RET proto-oncogene there is insufficient evidence to provide guidance as to the risk of medullary thyroid carcinoma. We present a family with the rare RET mutation, D631Y in which the proband initially presented with a pheochromocytoma, and review the available literature pertaining to this mutation. In 83% of index cases, pheochromocytoma was the presenting feature and only 37% of adult germline mutation carriers have developed medullary thyroid carcinoma, none of whom have been reported to have nodal or metastatic disease. Patients with a D631Y RET mutation typically present with pheochromocytoma and medullary thyroid carcinoma appears to occur with a later onset than reported with other RET mutations. Based on the current literature we recommend performing prophylactic total thyroidectomy by age 12 years for D631Y carriers although this recommendation may need to be reviewed as additional data becomes available.

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Parathyroid carcinoma, although a rare cause of primary hyperparathyroidism, carries a significant morbidity and mortality from severe symptomatic hypercalcaemia and related complications. We report a case where the diagnosis was not considered from the outset and review the current clinical and histopathological markers available to assist in the diagnosis of parathyroid carcinoma.

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BACKGROUND: Thyroid-stimulating hormone (TSH)-secreting pituitary adenomas (TSHoma) are a rare cause of thyrotoxicosis and need to be distinguished from the syndrome of resistance to thyroid hormone. Patients with TSHoma may also be misdiagnosed as having primary hyperthyroidism and receive inappropriate treatment directed towards the thyroid gland. METHODS: We performed a retrospective review of patients with TSHoma who presented to one New Zealand endocrine service between 1989 and 2003. RESULTS: Six patients with TSHoma were managed during this time period. All patients had elevated free thyroid hormone levels with elevated, or inappropriately normal, TSH levels. The median age at presentation was 43 years and the median time from symptom onset to correct diagnosis was 3 years (range 0.25-12 years). Five patients had a macroadenoma at the time of diagnosis. Three had been treated elsewhere for primary hyperthyroidism prior to referral. Three patients received octreotide as primary treatment with two of these patients later undergoing transsphenoidal resection of the pituitary adenoma. CONCLUSION: With increased awareness and earlier diagnosis of TSH-secreting pituitary adenomas, management can be appropriately directed towards the pituitary.

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BACKGROUND: Thyrotoxic, hypokalaemic periodic paralysis (TPP) is a reversible cause of severe muscle weakness that occurs in a small minority of thyrotoxic patients. Most cases to date have been reported in Asian men. AIMS: To evaluate the ethnic distribution of patients with TPP. METHODS: Retrospective analysis of all patients presenting with thyrotoxicosis and hypokalaemia with paralysis to two New Zealand hospitals. RESULTS: Seventy-one per cent of the 21 patients with TPP were of Polynesian ethnicity (Maori and Pacific Islander), 24% Asian and 5% European. Based on population demographics, these figures suggest a 37-fold overrepresentation for Polynesians and 159-fold for Asians compared with New Zealand Europeans. CONCLUSION: Polynesian, in addition to Asian people, are two ethnic groups at particular risk of TPP, and this condition must be considered in the differential diagnosis for patients presenting to the emergency department with severe hypokalaemia and weakness.

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Paragangliomas (PGLs) are rare tumours arising from parasympathetic-associated paraganglia (particularly of the head and neck) or from sympathetic-associated paraganglia such as in the adrenal medulla when they are termed phaeochromocytomas and at extra-adrenal sites in the abdomen and thorax. Recent reports have found frequent germline mutations of VHL, RET, SDHB or SDHD not only in familial cases but also in apparently sporadic cases of phaeochromocytoma. These germline mutations are particularly likely to be found if multifocal disease is present or if the phaeochromocytoma or PGL occurs at a young age. We report a germline splice site mutation in SDHB in a patient presenting with an incidental, apparently sporadic, abdominal sympathetic PGL at 68 years of age.

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