Purpose Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome of abnormal phosphate and vitamin D metabolism caused by typically small endocrine tumors that secrete fibroblast growth factor 23 (FGF23). TIO is characterized clinically by progressive musculoskeletal pain, fatigue, proximal muscle weakness, and multiple fractures, leading to long-term disability. Misdiagnosis and delayed diagnosis are common because of the non-specific symptoms, and several years may elapse before patients receive an accurate diagnosis and appropriate treatment. Thus, it is vital that awareness of the appropriate recognition and management of TIO is increased among healthcare professionals who may encounter patients with suspected TIO. Methods A roundtable meeting was held on 10 January 2020 in Dallas, TX, USA to gather perspectives on the diagnosis and treatment of TIO. The following topics were considered: clinical presentation, patient history, differential diagnosis, laboratory assessment, imaging, venous sampling, and treatment. Results This report provides a summary of our collective experiences in the management of TIO. Main conclusions Laboratory tests are mandatory to expedite TIO diagnosis and should include measurement of fasting serum phosphorus, renal phosphate reabsorption, serum 1,25-dihydroxyvitamin D, and serum FGF23 levels. Functional and anatomical imaging are essential to locate the FGF23-secreting tumor(s) causing TIO. Surgical resection is often a curative treatment when the tumor can be localized; however, better management of non-operable patients with targeted therapies is needed. Further efforts to increase awareness of TIO within the medical community, and education on recommended diagnostic and treatment pathways are required to improve the management of this debilitating disease.

An 18-year-old woman presented with a 6-month history of amenorrhoea and hyperandrogenism. Three months later she developed several episodes of fasting hypoglycaemia and was subsequently diagnosed with an insulinoma. Hyperinsulinaemia was observed in association with an elevated serum testosterone level. Surgical removal of the insulinoma resulted in resolution of the clinical and biochemical features of the polycystic ovarian syndrome (PCOS). Polycystic ovarian syndrome is unusual in a patient having an insulinoma. The rarity of this association may be the result of the late age of onset of this type of tumour, intermittent secretion of excessive insulin by the tumour, the degree of hyperinsulinism or other factors extrinsic to the insulin receptor that may facilitate insulin activity. However, we could not discover how our patient differs in having had PCOS from the majority of women with insulinoma who do not. If other patients with insulinoma are subsequently found to have hyperandrogenism, then this tumour might be added to the differential diagnosis of causes of anovulatory cycles and hyperandrogenaemia, although rare the association would be uncommon.

Objective: The objective of this retrospective and cross sectional study was to assess the correlation of aging and body mass index (BMI) with hormones from hypothalamic-pituitary-gonadal (HPG) in patients with and without diabetes mellitus (DM). Research Design and Methods:Electronic medical records of 605 patients were selected using specific exclusion criteria. The subjects were systematically divided into two experimental groups, with and without DM.Results: There was a significant negative correlation between age and serum free testosterone and significant positive correlations between age and serum LH and FSH in both groups. BMI was significantly higher in diabetics. In diabetics, BMI was negatively correlated with free testosterone, but no relationship with LH or FSH existed. In contrast, in nondiabetics, BMI was negatively correlated with LH and FSH only. In diabetics, a significant reverse correlation between HbA1c and free testosterone was present and they also had significantly lower FSH. Inappropriately normal LH with low free testosterone levels were seen in majority of patients from both groups. But more diabetics had inappropriately normal FSH with low free testosterone, 88% of diabetics and 70% of control group p<0.01. Conclusion:The data from this cross sectional study showed aged men, in both cohorts, had lower free testosterone and higher LH and FSH. Patients with good blood sugar control had higher serum free testosterone. In addition, FSH was significantly lower and impaired FSH response to low free testosterone was more pronounced in subjects with diabetes.