High rate of IIA/IIB neck groups involvement supports complete lateral neck dissection in thyroid carcinoma

Level II lateral neck dissection for papillary thyroid carcinoma: A retrospective cohort study

BACKGROUND

For N1b papillary thyroid carcinoma (PTC) patients, lateral neck dissection encompassing levels Ⅱ-Ⅴ is generally recommended. However, routine level Ⅱ dissection is controversial given the low incidence of metastasis, and potential complications such as increased shoulder syndrome.

METHODS

Retrospective analysis of consecutive patients with papillary thyroid carcinoma who underwent lateral neck dissection at a single institution from January 2019 to April 2021 was performed. Clinicopathological features such as age, gender, tumor location, tumor size, TgAb and TPOAb levels, capsular invasion, multifocality and lymph node metastases were examined to evaluate the occurrence of metastatic Level Ⅱ lymph nodes.

RESULTS

Overall and occult level Ⅱ metastases were observed in 51.83% and 34.84% of cN1b PTC patients. Multivariant analysis showed that primary tumor, location of primary tumor and positive level Ⅴ can serve as independent risk factors of metastasis in level Ⅱ. For cN1b PTC patients not suspected of level Ⅱ lymph nodes preoperatively, independent risk factors for predicting occult level Ⅱ metastases may include the location of primary tumor, positive level Ⅲ and positive level Ⅴ.

CONCLUSION

A significant number of patients with PTC and lateral neck disease experienced Level Ⅱ metastasis, with the location of primary tumor and multilevel lymph node involvement being the independent risk factors. If the tumor is less than 1 cm and located at lower 2/3 lobe, there is minimal possibility of level Ⅱ lymph node metastasis.

Clinical analysis of cervical lymph node metastasis patterns and multivariate factors in differentiated thyroid carcinoma

The incidence rate of thyroid cancer is rising rapidly in numerous parts of the world, but the mortality rate is relatively stable or even declining. The aim of the present study was to analyze the risk factors of cervical lymph node metastasis (LNM) in differentiated thyroid carcinoma (DTC). The clinical data of 846 patients with DTC were collected from the Department of General Surgery of Chifeng Municipal Hospital of Inner Mongolia Medical University (Chifeng, China) from June 2018 to June 2022. The relationship between central LNM (CLNM) and lateral LNM (LLNM) was explored in terms of sex, age, tumor diameter, multifocality, capsular invasion and Hashimoto's thyroiditis. It was revealed that male sex, age <35 years, tumor size >1 cm, multifocality and capsular invasion were associated with CLNM and LLNM (P<0.001), while there was no relationship between Hashimoto's thyroiditis, CLNM and LLNM (P>0.05). The number of positive lymph nodes in CLNM dissection, accounting for ≥50% of the total number of lymph nodes dissected, was significantly associated with LLNM (P<0.0001). In conclusion, there was no correlation between Hashimoto's thyroiditis and CLNM and LLNM. The present study revealed that patients with the characteristics of sex, age <35 years, tumor size >1 cm, multifocality and capsular invasion were associated with cervical LNM. The proportion of the number of central lymph node metastases to the total number of lymph nodes cleared during surgery is more than or equal to 50%, indicating a susceptibility to external cervical lymph node metastasis. The results of multivariate logistic analysis showed that male sex, multifocality, capsular invasion and CLNM were risk factors for LLNM, and age was a protective factor for LLNM in DTC.

Patterns of lymph node metastasis in level IIB and contralateral level VI for papillary thyroid carcinoma with pN1b and safety of low collar extended incision for neck dissection in level II

OBJECTIVE

To explore relevant clinical factors of level IIB and contralateral level VI lymph node metastasis and evaluate the safety of low-collar extended incision (LCEI) for lymph node dissection in level II for papillary thyroid carcinoma (PTC) with pN1b.

METHOD

A retrospective analysis was performed on 218 patients with PTC with pN1b who were treated surgically in the Head and Neck Surgery Center of Sichuan Cancer Hospital from September 2021 to May 2022. Data on age, sex, body mass index (BMI), tumor location, maximum tumor diameter, multifocality, Braf gene, T staging, surgical incision style, and lymph node metastasis in each cervical subregion were collected. The chi-square test was used for comparative analysis of relevant factors. All statistical analyses were completed by SPSS 24 software.

RESULT

Each subgroup on sex, age, BMI, multifocality, tumor location, extrathyroidal extension, Braf gene, and lymphatic metastasis in level III, level IV, and level V had no significant difference in the positive rate of lymph node metastasis in level IIB (P > 0.05). In contrast, patients with bilateral lateral cervical lymphatic metastasis were more likely to have level IIB lymphatic metastasis than those with unilateral lateral cervical lymphatic metastasis, with a statistically significant difference (P = 0.000). In addition, lymph node metastasis in level IIA was significantly associated with lymph node metastasis in level IIB (P = 0.001). After multivariate analysis, lymph node metastasis in level IIA was independently associated with lymph node metastasis in level IIB (P = 0.010). The LCEI group had a similar lymphatic metastasis number and lymphatic metastasis rate in both level IIA and level IIB as the L-shaped incision group (P > 0.05). There were 86 patients with ipsilateral central lymphatic metastasis (78.2%). Patients with contralateral central lymphatic metastasis accounted for 56.4%. The contralateral central lymphatic metastasis rate was not correlated with age, BMI, multifocality, tumor invasion, or ipsilateral central lymphatic metastasis, and there was no significant difference (P > 0.05). The contralateral central lymphatic metastasis in males was slightly higher than that in females, and the difference was statistically significant (68.2% vs. 48.5%, P = 0.041).

CONCLUSION

Lymphatic metastasis in level IIA was an independent predictor of lymphatic metastasis in level IIB. When bilateral lateral cervical lymphatic metastasis or lymph node metastasis of level IIA is found, lymph node dissection in level IIB is strongly recommended. When unilateral lateral cervical lymphatic metastasis and lymphatic metastasis in level IIA are negative, lymph node dissection in level IIB may be performed as appropriate on the premise of no damage to the accessory nerve. LCEI is safe and effective for lymph node dissection in level II. When the tumor is located in the unilateral lobe, attention should be given to contralateral central lymph node dissection because of the high lymphatic metastasis rate.