Robert L. Witt, MD, FACS, Editor

A historic diagnostic leap was ushered in decades ago with fine-needle aspiration cytology (FNAC) for the palpable thyroid nodule. Benign FNAC eliminated the need for diagnostic thyroid surgery in many instances. FNAC less commonly makes a diagnosis of thyroid cancer. Indeterminate FNAC is an active area of surgical intervention, although only a relatively small percentage of the large number of diagnostic thyroid procedures have yielded a final diagnosis of cancer.

The next diagnostic leap has been the use of thyroid ultrasound that has led to refinement in characterizing suspicious features of many thyroid nodules and identification of impalpable thyroid nodules. Subsequent popularization of ultrasound-guided FNAC has led to the diagnosis of smaller and smaller thyroid nodules with cancer and accounts in large part to the swift rise in the reported incidence of thyroid cancer in North America and elsewhere.

One ongoing diagnostic challenge is the unfortunate circumstance of completion thyroidectomy in cases of indeterminate FNAC and frozen-section analysis that is proven to be cancer on final pathology several days after diagnostic thyroid lobectomy. A second more common challenge remains the high rate of diagnostic thyroid surgery for indeterminate nodules that is ultimately proved benign and in retrospect was unnecessary surgery for the patient. Fine-needle aspiration (FNA) with molecular alteration testing has high diagnostic specificity and positive predictive value. It holds considerable promise in reducing the need for completion thyroidectomy. FNA with gene expression testing has high diagnostic sensitivity and negative predictive value. It portends to reduce the number of unnecessary diagnostic thyroid surgeries.

Fundamental to thyroid surgical management is an intimate understanding of thyroid, parathyroid, and neck anatomy, including neural and vascular structures. Technical innovations prompt us to compare time-honored classic open approaches with video-assisted, endoscopic, and robotic approaches. Extent of thyroid and neck surgery has long had forceful, sometimes opposing opinions. Molecular alteration testing will add fuel to the debate initially, but portends to lead to a personalized targeted surgical approach in the not too distant future.

Prognostication for survival and recurrence in patients with thyroid cancer has relied on a number of risk-stratification schemes. Molecular alteration testing is on the horizon to enhance prognostication for the individual patient.

Few fields in medicine rival the dynamism of modern thyroid diagnosis, management, and prognostication.