Medullary carcinoma of the thyroid. An update of diagnostic and prognostic factors.

Medullary carcinoma of the thyroid gland (MCT) is a disease which shows an early tendency to spread both locally as well as by the blood stream. It is to day possible to make an early diagnosis in patients who have the familial form of the disease as well as perform an organ specific localization regarding possible spread of the disease. Calcitonin is a major product of MCT cells and represent the most used tumour marker for diagnosis and evaluation of prognosis. Basal calcitonin levels are not suited for making neither an accurate diagnostic or prognostic evaluation. Calcitonin provocation test (pentagastrin injections, calcium infusion/injection or a combination) are recommended for both early diagnosis as well as follow-up studies for mapping of the extent of disease. An early diagnosis can be made in kindred of a patient with familial MCT. Selective venous catheterization will in a significant way aid the localization of the disease, and together with calcitonin provocation tests reveal the presence of micro-metastases.