[Surgical treatment of locally advanced differentiated thyroid carcinoma]

Patients with differentiated thyroid carcinoma (DTC), especially with papillary carcinoma, occasionally have direct tumor extension with invasion of surrounding tissues The presence of extrathyroidal invasion is one of the most important risk factors for mortality from DTC. However, leaving microscopic DTC on the surrounding structures usually does not lead to decreased survival or increased locoregional recurrence. Although endoscopic examinations, computed tomography, magnetic resonance imaging, and clinical presentations including hoarseness, dyspnea, and dysphagia are useful for the diagnosis of extrathyroidal extension, it is not easy to discriminate cancer invasion of adjacent structures from cancer adhesion preoperatively. The optimal surgical approach in patients with locally advanced DTC is controversial. Some experts support a conservative shave excision. They claim that these high-risk patients frequently have distant metastases and tumor dedifferentiation, and that survival advantage from extended surgery at the expense of significant morbidity is unclear. Others advocate an aggressive en bloc resection of the tumor and involved vital structures when technically feasible, because elimination of the risks of suffocation or major vessel hemorrhage is beneficial to patients. This paper discusses the management of patients with locally advanced DTC involving the recurrent laryngeal nerve, laryngotrachea, esophagus, major vessels, and mediastinum.