Surgical Treatment of Differentiated Thyroid Carcinoma Originating in the Isthmus (a Literature Review)

Papillary thyroid carcinoma originating in the isthmus accounts for 1.0%-9.2% of papillary thyroid carcinoma.There is no specific thyroid cancer originating in the isthmus treatment guidelines including American Thyroid Association (ATA), British Thyroid Association (BTA), European Thyroid Association (ETA). The characteristics of thyroid cancer in isthmus was as follows:1 Thyroid carcinoma of the isthmus is more likely to invade the capsule, multifocal lesions and central lymph node metastasis. 2 Expanded resection of the isthmus is only applicable to selected cases. Most isthmus cancers undergo total thyroidectomy. 3 Papillary thyroid carcinoma is a low-grade malignant tumor with rare distant metastases. It is mainly metastasized to the lungs and bones and the prognosis is poor. 4 There is no report of distant metastasis of thyroid isthmus. Conclusions:1 Thyroid isthmus cancer is still a malignant tumor with a good prognosis. 2 Biological characteristics: multifocal; easy to central lymph node metastasis (anterior larynx, pretrachea); easy to invade the capsule, resulting in tracheal, ribbon muscle invasion; tumor diameter size with central lymph node metastasis was not significantly related. 3 Surgery is still controversial, with total thyroidectomy+ bilateral central area dissection, some patients consider extended thyroid isthmusectomy.