Abstract
The 2010 Japanese clinical guideline for thyroid tumor has three risk classifications for papillary cancer: high-risk, low-risk, and gray-zone. Total thyroidectomy is recommended for high-risk cancer, and hemithyroidectomy is permitted for low-risk cancer. On the other hand, the limits of resection are not decided for unilateral thyroid papillary cancer in the gray-zone. We present 372 cases with papillary cancer in the gray-zone, and hemithyroidectomy was performed for 355 of these cases. Among the 355 cases, total thyroidectomy was added due to local recurrence and/or iodine isotope for lung metastasis for 19 cases. In the 19 cases, 14 cases have survived without recurrence, and only 2 cases died due to lung metastasis. From these data, hemithyroidectomy for unilateral papillary cancer in the gray-zone is permitted. Permanent postoperative paralysis of recurrent laryngeal nerve was observed in only one case of 372 cases with gray-zone cancer. Permanent postoperative hypoparathyroidism was observed in only one case of 17 cases who underwent total thyroidectomy. We did not select hemithyroidectomy due to concerns about postoperative complications.
