Endocrine Abstracts

Large corticotroph adenomas are uncommon pituitary mass lesions, representing around 10% of cases of Cushing's disease, and are often found to be locally invasive. 'Silent' corticotrophinomas stain for ACTH, but do not secrete sufficient ACTH to cause Cushing's disease. We describe a patient with an unusual mass presentation of a pituitary adenoma in whom there was also a marked discrepancy between the clinical and laboratory findings in the assessment of suspected Cushing's d...

Sunitinib and sorafenib are orally active tyrosine kinase inhibitors which have recently been developed as therapy for renal cell cancer and gastro-intestinal stromal tumours. Changes in thyroid function are frequently found during sunitinib therapy, typically occurring 7–24 months into therapy; the mechanism is not clear, though inhibition of iodine uptake, thyroid follicular cell apoptosis and thyroiditis have all been proposed. In contrast, thyroid dysfunction is repor...

Vitamin D is commonly used in the treatment of hypoparathyroidism after thyroid surgery. It is well recognised that excess vitamin D therapy leads to hypercalcaemia, and that this effect may be prolonged, lasting upto several weeks with some vitamin D preparations. We describe a case of severe, life threatening hypercalcaemia from vitamin D therapy, in which the duration of action of vitamin D was exceptionally long. A 51 year old lady presented with acute, severe haemorrhagic...

Radio-iodine is a safe and effective treatment of thyrotoxicosis, but carries a risk of the late development of hypothyroidism several years after therapy. Patients treated with radio-iodine require long-term follow-up to ensure that late hypothyroidism is detected and treated. Current changes in health care commissioning propose an increasing reliance on primary care for the long term follow-up of patients with thyroid disease. We report a study of the 8 year follow-up of 100...

Isolated hypogonadotrophic hypogonadism (IHH) is defective secretion of luteinizing hormone (LH) and follicular stimulating hormone (FSH) resulting in incomplete or absent pubertal development and infertility. Several genetic defects underlying IHH have been identified, including in the gonadotrophin releasing hormone receptor (GnRH-R) gene. Here we report a case of two sisters, with clinical phenotypes of IHH, presenting with poor breast development, primary amenorrhoea and a...

Macroprolactin is a high molecular weight IgG-prolactin complex which has reduced bioactivity. Macroprolactinaemia is a relatively common phenomenon, accounting for upto 20% of cases of hyperprolactinaemia in clinical practice; in the absence of amenorrhoea or hypogonadism these patients do not usually need dopamine agonist therapy. To ensure appropriate detection and management of such patients we routinely screen all serum samples with hyperprolactinaemia (>600 mU/l) for ...

Macroprolactin is a high molecular mass prolactin isoform found in some normal individuals. The most common form of macroprolactin arises from binding of prolactin to IgG ('big-big' prolactin), with a molecular mass 150-170 kD. A further prolactin isoform of intermediate size ('big' prolactin, 50-60 kD), has also been described but the nature and significance of this form is less clearly understood.We have previously described the effects of pregnancy in...

Hyperprolactinaemia in the presence of pituitary tumour can occur from tumour secretion or from stalk compression causing loss of dopaminergic inhibition. It is generally accepted that, in the presence of a large pituitary mass, a serum prolactin level up to 3000mU/l indicates stalk compression rather than a prolactinoma; the clinical diagnosis of prolactinoma depends on the degree of hyperprolactinaemia in the context of pituitary tumour size. Our aim was to examine more form...