Thyroid Cancer Diagnosis

There are four types of thyroid cancer: papillary, follicular, medullary and anaplastic, and most are highly curable with proper treatment. Papillary or follicular tumors are differentiated tumors and make up ninety percent of thyroid cancers. Medullary and anaplastic cancers are poorly differentiated tumors and make up the remainder.

Many patients in the early stages of thyroid cancer have no symptoms. As the cancer progresses, symptoms may include a lump or nodule in the front of the neck, hoarseness, neck or throat pain, enlarged lymph nodes, and/or difficulty swallowing, breathing, or speaking may occur.

Early stage thyroid cancer is nearly 100 percent curable with local therapies. The patient's outlook or prognosis declines a little with lymph node involvement or lung metastases at presentation.

Primary diagnosis and staging of thyroid cancer is generally determined on patient history, physical examination, laboratory testing, ultrasound, thyroid scintigraphy and biopsy.

PET/CT imaging is not normally used in the diagnosis or characterization of primary thyroid masses, but if increased radiopharmaceutical uptake is noted in a thyroid nodule as part of a whole-body study for cancer imaging, there is a moderately high risk that the nodule is malignant and should be evaluated further. Other diseases that could also cause increased uptake of radiopharmaceutical include Graves' disease and thyroiditis.

PET scanning may help by evaluating the cancer and determining the stage of the cancer, so the most appropriate therapy and treatment can be prescribed.

Source: Atlas of Clinical Positron Emission Tomography by Sallie F. Barrington, Michael N. Maisey and Richard R. Wahl. Oxford University Press, Inc. New York, NY. 2006.

Practical FDG Imaging: A Teaching File by Dominique Delbeke, William H. Martin, James A Patton and Martin P. Sandler. Springer-Verlag New York, Inc. 2002.