Features of papillary thyroid microcarcinoma associated with lateral cervical lymph node metastasis.

Papillary thyroid microcarcinoma (PTMC) has an excellent prognosis with an indolent disease course. However, some PTMCs have an aggressive course with lateral cervical lymph node (LCLN) metastasis or distant metastasis. This study aimed to evaluate the pre-operative features of PTMC associated with LCLN metastasis. This retrospective cohort study with a nested, matched case-control design included 199 PTMC patients with LCLN metastasis at initial surgery (N1b group) and 196 PTMC patients without any LN metastasis or persistent disease (N0 NED group) as controls; primary tumour sizes were matched. Compared with the N0 NED group, the N1b group was younger (<50 years) and more likely to be male (P = 0·002 and P = 0·003, respectively). On pre-operative neck ultrasonography (US), N1b group PTMCs were more commonly associated with a location in the upper lobes of the thyroid, or in the subcapsular area and microcalcifications than N0 NED group PTMCs (all P < 0·001). An increase in the number of these features was significantly associated with a higher risk of LCLN metastasis (P < 0·001). Evaluation of the clinical and pre-operative US characteristics of 26 patients with confirmed LCLN recurrence after initial treatment of clinical N0 PTMCs revealed that the distribution of the number of suspicious features in these patients was similar to that of the N1b group. Papillary thyroid microcarcinomas in young (<50 years) or male patients, with an upper lobe or subcapsular location, and with microcalcification have a higher risk of LCLN metastasis. Individualized management according to the number of these suspicious features may be needed for small thyroid nodules.

Jeon MJ ，Chung MS ，Kwon H ，Kim M ，Park S ，Baek JH ，Song DE ，Sung TY ，Hong SJ ，Kim TY ，Kim WB ，Shong YK ，Lee JH ，Kim WG ... -  《-》

Preoperative Clinical and Sonographic Predictors for Lateral Cervical Lymph Node Metastases in Sporadic Medullary Thyroid Carcinoma.

Oh HS ，Kwon H ，Song E ，Jeon MJ ，Song DE ，Kim TY ，Lee JH ，Hong SJ ，Kim WB ，Shong YK ，Baek JH ，Kim WG ... -  《-》

Predictors of lateral lymph node metastasis and skip metastasis in patients with papillary thyroid microcarcinoma.

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 management and prognosis. Previous studies have focused on post-surgery risk factors for cervical LN metastasis. This study aims to identify predictors of lateral LN metastasis by analyzing pre-operative ultrasonographic findings alongside clinicopathological factors. 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 compares patients with lateral LN metastasis (N1b) to age- and sex-matched patients without LN metastasis (N0). Subgroup analysis was performed to evaluate risk factors of skip metastasis. The study included 90 patients with PTMC with lateral LN metastasis (N1b) and 268 age- and sex-matched patients without LN metastasis (N0). The mean age was 49.3 years, and female patients were dominant in both groups. Structural recurrences of 4.4% (4/90) were observed only in the N1b group. The N1b group exhibited a higher frequency of upper lobe tumor location compared to the N0 group (38.9% vs. 16.0%, p < 0.001). There was no significant difference in the locations with the presence of invasion to adjacent organs. 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). There were no differences in echogenicity, sonographic feature, margin, and AP diameter of the thyroid gland between the two groups. In multivariate analysis, independent risk factors for lateral LN metastasis included extrathyroidal extension, multiplicity, upper lobe tumor location, and non-parallel shape. Skip metastasis in patients with PTMC was associated with upper lobe tumor location. Detailed ultrasound examinations, evaluating tumor location, number, orientation, and the presence of ETE, are crucial in accurately predicting lateral LN metastasis especially when primary tumor was in the upper lobe to avoid missing skip metastasis. These evaluations can help guide the decision between AS and immediate surgery in patients with PTMC.

Yoon JH ，Park JY ，Hong AR ，Kim HK ，Kang HC ... -  《-》

Clinicopathological Features and Molecular Signatures of Lateral Neck Lymph Node Metastasis in Papillary Thyroid Microcarcinoma.

Lim J ，Lee HS ，Heo JH ，Song YS ... -  《-》

Extensive lymphatic spread of papillary thyroid microcarcinoma is associated with an increase in expression of genes involved in epithelial-mesenchymal transition and cancer stem cell-like properties.

Active surveillance is an alternative management for patents with low-risk papillary thyroid microcarcinoma (PTMC); however, there is an absence of specific molecular markers that predict its progression. We compared gene expression patterns between PTMC with lateral neck-node metastasis (N1b) and PTMC-lacking nodal metastasis (N0). We performed oligonucleotide microarray analysis in three PTMCs without cervical lymph-node metastases (N0), and five PTMCs with lateral neck-node metastasis (N1b) at initial diagnosis, using an Illumina HumanHT-12 v4.0 Expression BeadChip. Quantitative real-time PCR (qPCR) and western blot analysis confirmed microarray data. We performed immunohistochemistry (IHC) to confirm protein overexpression in samples from 20 N0 and 24 N1b PTMC patients who underwent thyroidectomy. Microarray analyses identified 52 probes corresponding to 45 genes. Expression of these genes differed significantly between the two PTMC groups. Forty genes were significantly upregulated and five genes were downregulated in N1b PTMC compared to N0. Four genes related to epithelial-to-mesenchymal transition (EMT) and stem cell markers, including ALDH1A3, TM4SF1, PROM1, and CAV1 were significantly upregulated in N1b PTMCs. Real-time qPCR confirmed this expression and western blot analysis confirmed higher expression of ALDH1A3, TM4SF1, PROM1, and CAV1 in N1b than in N0 PTMCs. IHC indicated overexpression of ALDH1A3 and CAV1 in N1b compared to N0 PTMCs. Genes related to EMT and thyroid cancer stem cell-like properties are upregulated in early extensive lymphatic spread of PTMC.

Lee S ，Bae JS ，Jung CK ，Chung WY ... -  《-》