Endocrine Abstracts

Background: Papillary thyroid microcarcinoma (PTMC) is characterized by its favorable prognosis and potential for active surveillance (AS) as a management option. However, the presence of cervical lymph node (LN) metastasis, especially lateral LN metastasis, significantly impacts both management and prognosis. This study identified predictors of lateral LN metastasis by analyzing pre-operative ultrasonographic findings alongside clinicopathological factors.

Methods: A retrospective review of medical records was conducted for patients with PTMC who underwent surgery at Chonnam National University Hwasun Hospital between 2004 and 2013. This is a case-control study that compared patients with lateral LN metastasis to age and sex-matched patients without LN metastasis.

Results: The study included 90 PTMC patients with lateral LN metastasis (N1b) and 268 age and sex-matched patients without LN metastasis (N0). Structural recurrences of 4.4% (4/90) were observed in the N1b group only. The N1b group exhibited a higher frequency of upper lobe tumor location as compared to the N0 group. A higher proportion of non-parallel shape was observed in the N1b group than the N0 group (80.0% vs. 66.0%, p =0.013). In multivariate analysis, independent risk factors for lateral LN metastasis included extra-thyroidal extension (ETE), multiplicity, upper lobe tumor location, and non-parallel shape.

Conclusions: Lateral cervical LN metastasis is a significant risk factor for structural recurrence in PTMC patients. Detailed ultrasound examinations, evaluation of tumor location, number, orientation, and the presence of ETE, are crucial in accurately predicting lateral LN metastasis. These assessments can help guide the decision between active surveillance and immediate surgery in patients with PTMC.