Papillary Thyroid Carcinoma Incidentally Found in Cervical Lymph Nodes During Neck Dissection for Patients With Tongue Squamous Cell Carcinoma: A 3-Case Report and Literature Review.

The incidence of papillary thyroid carcinoma (PTC) found in the cervical lymph nodes during neck dissection for patients with tongue squamous cell carcinoma (SCC) is infrequent, with the coexistence of PTC and SCC in the same cervical lymph node being the rarest. Some of these patients present with primary lesions in the thyroid gland, whereas others have no obviously malignant thyroid lesion. The reasons behind this clinical phenomenon and the relationship between tongue SCC and PTC found in the cervical lymph nodes are unclear. Moreover, for surgeons, making the choice between thyroid surgery and follow-up is still a clinical dilemma. Of the 956 patients who underwent neck dissection owing to maxillofacial tumors from January 2011 through December 2017 at Second Xiangya Hospital of Central South University, 3 with tongue SCC presented with PTC in the cervical lymph nodes. Neither the preoperative physical examination nor ultrasonography after surgery showed substantial nodules in the thyroid glands of these patients, so none of them underwent thyroid surgery or chemoradiotherapy. At follow-up (1 to 6.5 years), we found no obviously malignant lesions in the patients' thyroid glands or related metastatic disease. Our study suggests that tongue SCC may not affect the occurrence and development of PTC in the cervical lymph nodes. For patients with tongue SCC presenting with PTC in the cervical lymph nodes, it is not necessary to carry out thyroid surgery immediately if ultrasonography shows no substantially malignant lesion in the thyroid gland. Nevertheless, conducting periodic follow-up is very important.