The value of lymph-node dissection in patients with differentiated thyroid cancer.

The perithyroidal and ipsilateral cervical lymphatic system not only is commonly involved by thyroid cancer but also is a common site of recurrence. Modified radical neck dissection, with preservation of the sternocleidomastoid muscle and spinal accessory nerve, is the treatment of choice for patients with clinically evident lymph node metastases due to differentiated thyroid cancer. It is also recommended, by us, for patients over 40 years of age who have primary thyroid tumors greater than 1.5 cm in size whether or not nodes are clinically palpable. This is because at least 75 per cent of these patients have metastases, and their discernment at operation is unreliable. With more aggressive surgery, the recurrence-free survival rate can be improved substantially without cosmetic deformity or postoperative dysfunction.