The presence of distant metastases from differentiated thyroid carcinoma decreases the 10-year survival of patients by 50%. Bone metastases represent a frequent complication especially of follicular thyroid cancer and severely reduce the quality of life causing pain, fractures, and spinal cord compression. Diagnosis is established by correlating clinical suspicion with imaging. Imaging is essential to detect, localize, and assess the extension of the lesions and should be used in conjunction with clinical evidence. Bone metastases are typically associated with elevated markers of bone turnover, but these markers have not been evaluated in differentiated thyroid cancer. Skeletal and whole-body magnetic resonance imaging and fusion 2-deoxy-2-[18F]fluoro-D-glucose whole-body positron emission tomography/computed tomography (PET/CT) are the best anatomic and functional imaging techniques available in specialized centers. For welldifferentiated lesions, iodine-PET scan combined 124 I-PET/CT is the newest imaging development and 131 I is the first line of treatment. Bisphosphonates reduce the complications rate and pain, alone or in combination with radioiodine, radionuclides, or external beam radiotherapy and should be employed. Surgery and novel minimally invasive consolidation techniques demand an appropriate patient selection for best results on a multimodal approach. Basic research on interactions between tumor cells and bone microenvironment are identifying potential novel targets for future more effective therapeutic interventions for less differentiated tumors.

The ESCEO recommends that 50 nmol/L (i.e. 20 ng/mL) should be the minimal serum 25-(OH)D concentration at the population level and in patients with osteoporosis to ensure optimal bone health. Below this threshold, supplementation is recommended at 800 to 1000 IU/day. Vitamin D supplementation is safe up to 10,000 IU/day (upper limit of safety) resulting in an upper limit of adequacy of 125 nmol/L 25-(OH)D. Daily consumption of calcium- and vitamin-D-fortified food products (e.g. yoghurt or milk) can help improve vitamin D intake. Above the threshold of 50 nmol/L, there is no clear evidence for additional benefits of supplementation. On the other hand, in fragile elderly subjects who are at elevated risk for falls and fracture, the ESCEO recommends a minimal serum 25-(OH)D level of 75 nmol/L (i.e. 30 ng/mL), for the greatest impact on fracture.

A third of patients with paraganglial tumors, pheochromocytoma, and paraganglioma, carry germline mutations in one of the susceptibility genes, RET, VHL, NF1, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127, and MAX. Despite increasing importance, data for long-term prognosis are scarce in pediatric presentations. The European-American-PheochromocytomaParaganglioma-Registry, with a total of 2001 patients with confirmed paraganglial tumors, was the platform for this study. Molecular genetic and phenotypic classification and assessment of gene-specific long-term outcome with second and/or malignant paraganglial tumors and life expectancy were performed in patients diagnosed at !18 years. Of 177 eligible registrants, 80% had mutations, 49% VHL, 15% SDHB, 10% SDHD, 4% NF1, and one patient each in RET, SDHA, and SDHC. A second primary paraganglial tumor developed in

The SDHA, TMEM127, MAX, and SDHAF2 genes may contribute to hereditary pheochromocytoma and paraganglioma. Genetic testing is recommended in patients at clinically high risk if the classic genes are mutation negative. Gene-specific prevention and/or early detection requires regular, systematic whole-body investigation.

NR5A1 mutations are associated with 46,XX primary ovarian insufficiency and 46,XY disorders of sex development.