Endocrine Abstracts

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: 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.</...

Background: Acquired male secondary hypogonadism is a relatively common cause of referral to the endocrine clinic. However, the extent to which further investigation is required, and the indications for a trial of testosterone therapy, remain unclear. Aim To review the clinical/biochemical/radiological findings in men presenting with this condition.Methods: We performed a retrospective case analysis of 41 consecutive patients referred to our clinic over ...

Background: Heightened awareness, as well as frequent thyroid function testing, have contributed to a recent rise in the incidence of thyrotropinomas. Microadenomas are now increasingly being recognized. The classical textbook description of thyrotropinomas is based on historically reported features in patients who typically had large/invasive lesions. The phenotype of microTSHomas could therefore differ.Methods: We reviewed the records of all TSHomas re...

Background: Endocrine Society guidelines classify macroprolactinomas as ‘resistant’ if there is failure to normalise prolactin, or to achieve radiological tumour shrinkage of >50%, on standard doses of dopamine agonist. In this context, escalation of treatment to maximal tolerable doses and/or referral for surgery is advised. However, we have recently observed several ‘discordant responders’, where tumour shrinkage lags significantly (>6 months) beh...

Although MRI remains the investigation of choice for pituitary imaging, it does not provide information about ‘functionality’ of lesions (e.g. residual adenoma vs post-surgical scar tissue) and cannot reliably identify all microadenomas.We hypothesised that i) imaging with the PET ligand 11C-methionine, which is taken up at sites of peptide/protein synthesis, would permit more reliable identification of functioning pituitary adenoma ...

Although MRI remains the investigation of choice for pituitary imaging, it does not reliably identify all secretory microadenomas, and cannot always discriminate residual tumour from post-surgical change following hypophysectomy. We hypothesised that i) imaging with the PET ligand 11C-methionine, which is taken up at sites of peptide/protein synthesis, would permit more reliable identification of functioning pituitary adenoma, and ii) co-registration of PET–CT ...

Background: Pituitary carcinoma occurs in ~0.2% of resected pituitary tumours, and carries a poor prognosis (mean survival <4 years), with standard chemotherapeutic regimens showing limited efficacy. However, recent evidence suggests that temozolomide, an orally active alkylating agent used principally in the management of glioblastoma, may also be effective in controlling aggressive/invasive pituitary adenomas/carcinomas. Low levels of expression of the DNA-repair enzyme ...

Background: Although MRI remains the investigation of choice for pituitary imaging, it does not provide information about the ‘functionality’ of lesions (e.g. residual adenoma vs post-surgical scar tissue), and cannot reliably identify all microadenomas. These limitations are of particular relevance in acromegaly where clinical and biochemical evidence of disease activity mandates (further) treatment.Methods: We hypothesised that i) imaging wit...