Endocrine Abstracts

Introduction

Papillary and follicular thyroid carcinomas are the most common forms of endocrine carcinomas. Lymph node involvement seems to be a low risk factor for death, but it increases the risk for loco-regional recurrences and distant metastasis. Lymph node involvement is more seen in case of papillary thyroid carcinoma, less reported in vesicular carcinoma. The aim of this work is to determine the clinicopathologic predictive factors of central lymph node involvement.

Material and methods

A retrospective study of 75 patients treated for a differentiated thyroid cancer, between 2000 and 2016.

Results

Our population consisted of 75 patients (66 women and 9 men). The mean age was 44 years [15 years - 78 years]. The mean consultation delay was 19 months. Histologic types were: papillary thyroid carcinoma (92%) and vesicular thyroid carcinoma (8%). Total thyroidectomy was performed in 74 cases, associated with a central lymph node dissection in 69 cases: unilateral in 23% of cases and bilateral in 77% of cases. Lateral lymph node dissection was performed in 25 cases: unilateral in 16% of cases and bilateral in 84% of cases. Multifocal involvement was noted in 31% of cases. Extrathyroidal extension was detected in 19% of cases. We noted a lymph node involvement in 50.6% of patients: central in all cases and lateral in 16 cases. After statistical analysis, 2 factors were identified as predictive of central lymph node involvement: multifocality (P = 0.000) and extrathyroidal extension (P = 0.023). Sex, age, histological type, tumour size and presence of vascular emboli were not correlated with central node involvement. Involvement of the central area was not significantly predictive of the involvement of the lateral area (P = 0.105).

Conclusion

Prophylactic central neck dissection in differentiated thyroid cancer is controversial and should only be performed selectively in high-risk patients. Our study, as well as other studies, clearly shows the possibility to estimate pre and intraoperatively, the risk of lymph node involvement in differentiated thyroid carcinomas and thus avoid unnecessary prophylactic central lymph node removal with all its morbidity.