Calcitonin is a hormone secreted by the parafollicular thyroid cells. Diagnosis of medullary thyroid carcinoma (MTC) should be considered when high basal calcitonin levels or high calcitonin levels after specific provocative test are found. In this context, calcitonin is considered a relevant tumor marker for diagnosis and follow-up of MTC. In this manuscript, we review some issues related to the usefulness of measuring basal calcitonin in patients with thyroid nodules. The current available provocative tests for calcitonin are discussed. Finally, […]

The use of GH provocative tests to diagnose children with short stature continues to be a controversial issue. GH secretion is considered a continuum ranging from absent to normal secretion. When GH deficiency is severe, as in GH gene defects and craniopharyngiomas, there is a very important growth failure and absent or minimal GH response to stimulation tests. These situations could be used as standards to define total GH deficiency. However, partial GH deficiency also can show growth failure, but […]