This overproduction can often be demonstrated in the basal state but sometimes requires provocative testing with calcium infusion, glucagon, or pentagastrin. This is an exciting example of the diagnosis and treatment of significant but silent disease by a combination of genetic study and provocative endocrine testing. As a result of this approach, survival is better with the familial form, in which tumors are typically less than 3 cm in diameter when diagnosed, than with the sporadic form. Although Hodgkin's disease, other lymphoproliferative tumors, and other cancers can all metastasize to the thyroid, anaplastic cancers occasionally arise in the thyroid. They grow extremely rapidly, and local invasion leads to strangulation or esophageal obstruction, causing death within six to 12 months.
Patients usually have a discernibly growing mass and often exhibit stridor, hoarseness, or both.
Physical examination discloses a goiter and irregular extension into surrounding tissues. The outlook in such cases is grave, despite a combination of surgery, radiation therapy, and adjuvant chemotherapy. The application of molecular biology techniques has revealed some suggestive correlations between certain oncogenes and the pathogenesis of thyroid cancer. However, by far the most important clinical lesson relates to exposure to irradiation in childhood. The tragic explosion of a nuclear reactor at Chernobyl provided a reminder of this risk.