Thyroid cancer

The management and prognosis for thyroid carcinomas is very much related to the histologic type of the lesion and its extent when discovered. Papillary and follicular malignancies have long-term survival rates approaching that of an age-matched population when tumors are ''occult'' or intrathyroidal. Anaplastic carcinoma is a relatively uncommon lesion and has an exceptionally poor prognosis; about 60% of patients will be dead in six months. Medullary carcinoma is again much less common that papillary or follicular carcinoma. The tumor shows a wide variation in growth rate and 20-to-30 year survivals with delayed recurrences are not uncommon. Primary thyroid lymphoma is also variable in its natural history, depending mainly on the histologic type. Several imaging techniques have been used to evaluate patients with known or suspected thyroid malignancies. Ultrasonography is used mainly for screening purposes; radionuclide imaging is useful for both detecting and staging malignancies; while computed tomography is used infrequently to show the extent of a tumor that is likely to have extended beyond the capsule to involve the trachea or esophagus