A rare case showing an enlarged level I lymph node as the first symptom due to papillary thyroid microcarcinoma

As the high-pace development of sonography in recent years, the incidence of papillary thyroid carcinoma (PTC) has increased sharply worldwide, especially papillary thyroid microcarcinoma (PTMC). As we all know, PTMC is an indolent tumor, and level I lymph nodes (LNs) at a higher region relatively, so the majority of PTMCs admitted to surgery before the level I LNs metastasis. It is rare to see PTMC with level I LNs metastasis. At best of our known, there is only one Chinese research mentioned it but without a description of it. In this case, we reported a 30-year-old female who developed a recurrent submental cystic mass after being received treatment to remove a certain volume of light-yellow fluid. Pathology verified that mass in the submental area involved by PTMC. We consider that it may relate to age, multifocality, the diameter of PTMC, numbers of central compartment LNs, and "re-metastasis".