Publication:

The impact of ipsilateral central neck dissection on the 2015 American thyroid association risk stratification system and TNM staging in papillary thyroid carcinoma

Background In patients with classic papillary thyroid carcinoma (PTC) and no clinical evidence of lymph node metastasis (cN0), elective central neck dissection remains controversial. This study evaluates whether elective ipsilateral central neck dissection (eICND) along with total thyroidectomy could modify the staging of these patients. Additionally, we aim to assess pN1 risk factors, the incidence of post-operative complications, and the correlation between pN1 and change in tumor classification according to the risk stratification score of the American thyroid association 2015 (ATA 2015-RSS) and the TNM Score.

Methods This is a prospective, observational study, involving 46 patients with cN0 PTC who underwent eICND along with total thyroidectomy. The number of metastatic lymph nodes, the largest lymph node metastasis, and the extra-nodal extension were assessed.

Results 22 out of 46 patients (47.8%; CI 32.9–63.1) presented lymph node metastasis. Seventeen out of the 45 patients initially classified as low or intermediate ATA 2015-RSS upgraded their risk staging (37.8%; CI 23.8–53.5). Fourteen out of these reclassified patients had their initial ATA 2015-RSS changed due to lymph node metastasis larger than 2 mm (mostly between 3 mm and 4 mm). Ten out of 46 (21.7%; CI 10.49–36.4) patients had their TNM staging reviewed. General complication rate was 17.4% (8/46).

Conclusions Elective dissection of levels VI ipsilateral and VII showed the ability to upgrade the initial ATA 2015-RSS and TNM staging in patients with cN0 PTC. However, further studies are necessary to evaluate the clinical impact of lymph node micro-metastasis.