S1-contemporary Management of Differentiated Thyroid Cancer

DIAGNOSIS Management of differentiated thyroid cancer begins with diagnosis, usually surgical excision, and initial staging postoperatively. Diagnosis is achieved by history and exam, thyroid function tests and calcitonin (CT) assay, ultrasound, most frequently fine needle aspiration (FNA), sometimes isotope scans radiographs, computed axial tomography (CAT) scans or magnetic resonance imaging (MRI), and even positron emission tomography (PET) scans. Diagnostic methods and concepts are extensively reviewed in www.thyroidmanager.org/thyroidcancer to which readers are referred. Thyrotropin (TSH), free thyroxine (fT4) and thyroid peroxidase antibody (TPO-Ab) assays are needed to document the patient’s metabolic status and fitness for operation, to rule out a possible hyper functioning thyroid lesion, and sometimes to help differentiate thyroiditis as the etiology of the lesion of interest. Serum TG measurement is not recommended in routine practice preoperatively because elevated levels are associated with any thyroid growth. Ultrasound exam is currently central to diagnosis, providing information on the size, shape and number of lesions, probability of infiltrative disease, and of involved neck nodes. The key test is of course FNA and its interpretation, supplemented sometimes by assay of tumor genetic markers that can augment, or reduce, the statistical probability that the tumor is malignant. Whole body (WB) Scans for diagnosis of metastatic disease are performed if there is some suggestion of disease spread, but are more commonly conducted after operation. The results of the diagnostic workup may include definite or possible thyroid cancer within a nodule or thyroid lobe, and possible nodal or metastatic disease. Management of cancer in children, and of anaplastic and medullary tumors, is reviewed in Thyroidmanager.