Surgical management of the lateral neck compartment for metastatic thyroid cancer

PURPOSE OF REVIEW

The lateral neck compartment is the second most frequent target region for metastatic papillary thyroid cancer (PTC) and medullary thyroid cancer (MTC). Lateral lymph node metastases are associated with locoregional recurrence and, when they involve either side of the neck, with mediastinal and distant metastases.

RECENT FINDINGS

For tumors originating from the upper thyroid pole, the first nodal basin is not invariably the central compartment (as for primaries arising from the inferior thyroid pole) but often the upper part of the ipsilateral lateral compartment. Lymph node dissection of the first basin may differ depending on the location of the primary tumor. Involvement of the contralateral lateral compartment is seen in PTC with extensive central compartment involvement, and in MTC with preoperative basal calcitonin levels more than 200  pg/ml (normal limit <10  pg/ml).

SUMMARY

After lateral lymph node dissection for metastatic thyroid cancer, dysfunction of lateral neck nerves is fairly common. This observation underpins the importance of striking a balance between oncological benefit and surgical risk. Lateral lymph node dissection may be warranted for an upper thyroid pole primary, for a tumor with extensive involvement of the central compartment, and for an MTC with increased basal calcitonin level of 20-200  pg/ml (ipsilateral dissection) or more than 200  pg/ml (bilateral dissection).

Sentinel lymph node in thyroid tumors - own experience

AIM OF THE STUDY

To determine the feasibility of sentinel lymph node biopsy (SLNB) for the evaluation of the cervical lymph node status in patients with thyroid tumors.

MATERIAL AND METHODS

Twenty-three patients with suspected thyroid cancer were enrolled in the study. 0.5-1.0 ml of 1% Patent Blue dye was injected intratumorally. After SLNB, thyroidectomy and proper lymphadenectomy were performed.

RESULTS

Sentinel lymph node was detected in 20 (86.9%) patients. Thirty-one SLNs were found - 21 (67.7%) were located in the central neck compartment, 4 (12.9%) in the lateral neck compartment, 6 (19.4%) in the upper mediastinum. The number of SLNs ranged from 1 to 3 (mean 1.6). Sentinel lymph node was positive in 5 (25%) patients, negative in 15 (75%) in the final histopathology. Sentinel lymph nodes were located only in the central neck compartment in 13 patients, and in both the central and lateral neck compartments in 2 patients. In one patient, SLNs were located only in the central neck compartment and upper mediastinum. Three patients had SLNs only in the upper mediastinum, while one had them only in the lateral neck compartment. In one patient a node regarded as SLN was negative, while there were metastases in removed non-sentinel lymph nodes (NSLNs). In two patients, histopathology of SLNs showed that they were actually parathyroid glands.

CONCLUSIONS

Our results confirm that thyroid cancer SLNB is rather easy to carry out. Its performance along with intraoperative examination can help to avoid unnecessary lymphadenectomy. However, it should be kept in mind that parathyroid glands can be stained and removed by mistake during SLNB.

Gender-Specific Variation in the Prognosis of Papillary Thyroid Cancer TNM Stages II to IV

To investigate the correlation between gender and the clinical presentation of papillary thyroid cancer and the long-term followup results, 435 patients who underwent total or near-total thyroidectomy were enrolled in this study. Among these papillary thyroid cancer patients, 12.2% showed lymph node metastases and a higher incidence of male patients in the N1b group. There were 65 from 316 female (20.6%) and 49 from 120 male (40.8%) patients who had a postoperative disease progression. A total of 55 (12.6%) patients died of thyroid cancer. Male patients showed a higher thyroid cancer mortality than the females. Multiple regression analysis showed that male gender was an independent risk factor for cancer recurrence and mortality. Male patients with TNM stages II to IV of papillary thyroid cancer need to adopt aggressive surgical and postoperative (131)I therapy.

Clinical efficacy of sentinel lymph node biopsy using methylene blue dye in clinically node-negative papillary thyroid carcinoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) has recently been used to detect occult lymph node metastases. The aim of this study was to assess the feasibility and clinical efficacy of SLNB in the treatment of clinically node-negative papillary thyroid carcinoma.

METHODS

A total of 114 consecutive patients with clinically node-negative papillary thyroid carcinoma were enrolled and underwent SLNB. After injection of 1% methylene blue around the tumors, blue-stained sentinel lymph nodes (SLN) were collected from the central compartments. All the patients underwent total thyroidectomy with bilateral central compartment neck dissection after SLNB.

RESULTS

SLN were identified in 84 (73.7%) of the 114 patients. Of these 84 patients, 24 (28.6%) had metastases in the SLN. Among the 60 patients who had no metastases in their SLN in frozen biopsy samples, seven had metastatic foci in their SLN in the permanent biopsy samples and six had metastases in their non-SLN samples. Central compartment lymph node metastases were detected in 11 of the 30 patients in whom SLN were not identified. Thus, the sensitivity, specificity, and positive and negative predictive values of SLNB were 64.9, 100, 100, and 78.3%, respectively. The false-positive and false-negative rates were 0 and 35.1%, respectively. The detection of SLN led to no major complications.

CONCLUSIONS

SLNB using methylene blue in papillary thyroid carcinoma is a safe and technically feasible procedure. However, it is of limited use in the management of clinically node-negative papillary thyroid carcinoma because of low sensitivity and a high false-negative rate.

Sentinel lymph node biopsy in thyroid cancer: it can work but there are pitfalls

OBJECTIVE

The aim of this study is to retrospectively assess the specific perils associated with conducting sentinel lymph node biopsies to determine whether a central compartment neck dissection (CCND) is necessary in well-differentiated thyroid cancer. The goal was to assess the specific reasons for a false negative in 3 specific patients among a large population of thyroidectomy patients.

STUDY DESIGN

Case series with chart review.

SETTING

Three McGill University teaching hospitals that are part of the McGill University Thyroid Cancer Center in Montreal, Quebec, Canada.

SUBJECTS

Patients undergoing thyroidectomy and CCND for nodules suspicious for thyroid cancer (June 2009 to May 2010).

METHODS

Retrospective analysis of 157 patients who underwent thyroidectomy and analysis of CCND as a function of sentinel lymph node status on frozen section as determined by a pathologist at one of the participating centers.

RESULTS

Three patients were considered true failures or false negatives of the original protocol. These 3 patients were deemed to have benign lymph node status intraoperatively but were found postoperatively to harbor malignancy and therefore should have undergone CCND. The critical reasons for the imperfect false-negative rate are believed to be secondary to samples falsely deemed benign as well as multinodular disease.

CONCLUSION

The value of sentinel lymph node biopsy in thyroid cancer, although largely debated, appears to be strong. If caution is taken in using dedicated head and neck pathologists for sentinel lymph node cases, as well as properly addressing multinodular malignancy, clinical decision making can be rendered more objective.