Latest Progress in Risk-Adapted Surgery for Medullary Thyroid Cancer

Simple Summary Medullary thyroid cancer is a rare neuroendocrine tumor, which is inherited in 25% of cases. Medical progress has made it easier to find thyroid tumors before they spread to the neck nodes, which makes a surgical cure harder to achieve. Removing only the tumor-bearing thyroid lobe causes fewer surgical complications than removing the whole thyroid gland or neck nodes. When the remaining thyroid lobe produces enough thyroid hormone, patients are spared the need to take one thyroid hormone tablet daily for life. This literature review confirms that the removal of the tumor-bearing thyroid lobe alone clears all of the tumor in patients who are not gene carriers and whose thyroid tumors showed no 'desmoplasia' under the microscope on a rapid 'frozen section' examination. Gene carriers, who can be detected by a simple blood test, still need to have the whole thyroid gland removed so that no other thyroid tumors can form from the thyroid tissue left behind.Abstract (1) Background: The wider adoption of a preoperative ultrasound and calcitonin screening complemented by an intraoperative frozen section has increased the number of patients with occult sporadic medullary thyroid cancer (MTC). These advances offer new opportunities to reduce the extent of the initial operations, minimizing operative morbidity and the risk of postoperative thyroxin supplementation without compromising the cure. (2) Methods: This systematic review of the international literature published in the English language provides a comprehensive update on the latest progress made in the risk-adapted surgery for sporadic and hereditary MTC guided by an intraoperative frozen section. (3) Results: The current evidence confirms the viability of a hemithyroidectomy for desmoplasia-negative sporadic MTC. To add an extra safety margin, the hemithyroidectomy may be complemented by a diagnostic ipsilateral central node dissection. Despite the limited extent of the surgery, all the patients with desmoplasia-negative sporadic tumors achieved a biochemical cure with excellent clinical outcomes. A hemithyroidectomy decreases the need for postoperative thyroxine substitution, but a total thyroidectomy may be required for bilateral nodular thyroid disease. Hereditary MTC is a different issue. Because each residual thyroid C cell carries its own risk of malignant progression, a total thyroidectomy remains mandatory for hereditary MTC. (4) Conclusion: In experienced hands, a hemithyroidectomy, which minimizes morbidity without compromising the cure, is an adequate therapy for desmoplasia-negative sporadic MTC.