mutation-positive and cytologic indeterminate nodules are considered for total thyroidectomy, especially with BRAF mutations, to reduce the need for intraoperative pathologic consultation and to avoid a second surgery. In addition to the diagnostic value of molecular testing, the aggressive behavior of BRAF-positive PTCs provides prognostic information to refine patients’ management, including consideration of central neck dissection. Although still early in clinical application, the expanding knowledge of thyroid tumor biology has started translating into clinical practice, and molecular testing in thyroid FNA will be a valuable tool for diagnosis and better prognostication of thyroid cancer.
a radionuclide thyroid scan should be obtained for those with a low TSH to further evaluate the thyroid function. Thyroglobulin (Tg) level is not routinely measured as initial evaluation of thyroid nodule due to its lack of sensitivity and specificity as a screening tool. Serum calcitonin level and urine metanephrine should be obtained in patients with family history of medullary thyroid cancer or MEN IIA or IIB.
Any nodule with high-risk history if it is greater than 5 mm, with microcalcification, or any abnormal cervical lymph nodes
Greater than 1-cm solid nodule
Greater than 1.5-cm mixed nodule with any suspicious ultrasound features
Greater than 2.0-cm spongiform nodules or mixed nodule without any suspicious ultrasound features
be distinguished on cytology alone, because capsular or angiolymphatic invasion is required to make the diagnosis, which cannot be assessed from cytopathology.
TABLE 133.1 THE BETHESDA SYSTEM FOR REPORTING THYROID CYTOPATHOLOGY
development of suspicious sonographic features for malignancy, at which time a repeat FNA is warranted. Total thyroidectomy is recommended when the FNA report indicates malignancy. The FNA has a sensitivity of 97% to 99% (9). Recent prospective data from University of Pittsburgh Medical Center demonstrated 100% PPV and 100% specificity for BRAF-positive “follicular neoplasm” or “suspicious for malignancy” FNA (15). Another study showed 100% PPV in mutation-positive “FLUS” group, while the probability of malignancy for mutation-negative FLUS group is only 7.6% (34). The asterisk part in Figure 133.2 reflects our clinical practice based on above findings. Currently, it has not yet been fully validated or universally accepted. We believe the treatment algorithms will change in the near future as more data accumulate and molecular testing becomes more widely available.