Surgery for locally extensive carcinomas of the thyroid gland

Extrathyroidal extension of well-differentiated thyroid carcinoma has a significant impact on survival, reducing 10 year survival in half, and is associated with high rates of local, regional and distant recurrence. Up to 13% of patients with well-differentiated thyroid cancer will have extrathyroidal extension, and many of these will be asymptomatic, making thorough preoperative patient evaluation critical. The most commonly involved structures are the strap muscles, and the recurrent laryngeal nerve. The trachea, esophagus and larynx are involved less frequently. Complete surgical excision is the mainstay of treatment, and there are several important principles which should be followed. All gross disease should be removed, with preservation of functioning and vital structures when feasible. Tumors with extrathyroidal extension frequently harbor more aggressive subtypes such as Hürthle cell carcinoma, tall cell variants of papillary carcinoma or even poorly differentiated carcinoma. Because these variants are frequently less radioactive iodine avid, complete surgical resection is paramount. However, adjuvant therapy with radioactive iodine and external beam radiation are invariably needed. This article describes various surgical techniques for resection of thyroid cancer with extra thyroid extension.