Lymph node metastasis in suprasternal space and intra-infrahyoid strap muscle space from papillary thyroid carcinoma

Abstract

Background: This study was performed to evaluate the clinicopathologic characteristics of Lymph Node metastasis between investing layer of Cervical fascia and deep fascia of infrahyoid strap Muscles (LNCM) in papillary thyroid carcinoma (PTC). Methods: Retrospective review of patients with PTC who underwent thyroidectomy and central compartment neck dissection (CND) from January 2016 to January 2018 was performed in two tertiary referral academic medical centers. A total of 2104 consecutive patients with PTC who underwent thyroidectomy and CND were included in the retrospective review. The LNCM was resected as a separate specimen by the surgeon and the clinicopathologic characteristics of the patients were recorded. Multivariate logistic regression analysis was performed to identify risk factors for LNCM metastasis. Results: Of 2104 PTC patients, 451 patients (21.4%) had lymph nodes in the LNCM. Among them, 68 (15.1%) cases were confirmed to be positive in the LNCM. In total, the metastasis rate of LNCM in PTC patients was 3.2% (68/ 2104). Univariate analysis revealed that the metastasis of LNCM were more likely to have a primary site in the inferior pole, extrathyroidal extension (ETE), central cervical metastasis, level III and level IV metastasis. Multivariate analysis further showed tumor location in the inferior pole, ETE, level III and level IV metastasis conferred a significantly increased odds ratio for LNCM metastasis. Conclusion: Attention should be paid to the lymph tissue in the LNCM for PTC patients, especially in presence of a primary site in the inferior pole, ETE, level III and level IV metastasis.

Occult metastasis to the superficial level VI lymph nodes in papillary thyroid carcinoma

“…Multivariate analysis revealed that a primary tumor in the inferior pole, ETE, and level III/IV metastasis were associated with metastasis. 15 The superficial level VI in the current study appears to be similar to the lymph node group suggested by Yuan et al However, superficial level VI does not include the superficial area between the hyoid and cricoid cartilage as lymph nodes are rare in this superficial area. In this study, lymph nodes were harvested at superficial level VI in 48% of patients and occult metastasis to superficial level VI was observed in 4 (3.1%) patients.…”

“…Therefore, previous studies recommended dissecting the LNSS and SSLN in PTC patients with lateral compartment lymph node metastasis. 11,12,15,16 In addition, previous studies supported LNSS and SSLN dissection because it is a low risk and easy procedure.…”

“…16 In addition, Yuan et al suggested a group of lymph nodes between the investing layer of the deep cervical fascia and the infrahyoid strap muscle fascia. 15 This group seems to include the SSLN, LNSS, and the superficial area anterior to the larynx. In their study, lymph nodes in the dissected specimens were found in 21.4% of PTC patients.…”

“…The incidence and significance of metastasis to the LNSS and SSLN have not been clearly determined, although a few studies have investigated these points 11,12,14–16 . Further, it is difficult to differentiate between LNSS and SSLN in real operations.…”

Total thyroidectomy versus hemithyroidectomy with intraoperative radiofrequency ablation for unilateral thyroid cancer with contralateral nodules: A propensity score matching study

“…Inferior parathyroid glands were protected in situ or autotransplanted in the sternocleidomastoid muscle according to three certain types based on their blood supply and location [ 16 ]. All patients who underwent hemithyroidectomy with RFA received ipsilateral prophylactic central compartment neck dissection, and patients who underwent total thyroidectomy received ipsilateral prophylactic central compartment neck dissection on the side with the malignant lobe [ 17 , 18 ]. The ipsilateral CCND entailed the removal of the prelaryngeal, pretracheal, and right or left paratracheal nodal basins.…”