Risk Factors for Right Paratracheal Posterolateral Lymph Node Metastasis in Papillary Thyroid Cancer

Introduction: The incidence of papillary thyroid cancer (PTC) is increasing, and due to the favorable postoperative survival rates, the extent of surgery should be carefully determined, and complications during the operation should be avoided. The recurrent laryngeal nerve (RLN) divides the right paratracheal lymph node (RPTLN) into anteromedial and posterolateral compartments due to its anatomical course on the right and left sides of the neck, and the posterolateral lymph nodes are in close proximity to the RLN. Due to the risk of this complication, in this study, we aimed to determine the risk factors for the development of right paratracheal posterolateral lymph node (RPTPLLN) metastasis in PTC.
Materials and Methods: Between 2013 and 2022, patients who underwent central neck dissection (CLND) or central and lateral neck dissection due to the presence of PTC in the right lobe of the thyroid gland were included in the study. Descriptive data, along with preoperative imaging findings and postoperative pathology findings, were retrospectively evaluated.
Findings: The data of 55 patients who met the criteria were statistically analyzed. Of these patients, 24 (43.6%) were male and 31 (56.4%) were female. The mean age was 47.9±17.5 years (range: 16-81). The mean tumor size was 2.17±1.43 cm (range: 0.4-7.0). RPTPLLN was observed in 13 patients (23.6%). Univariate analysis revealed that extrathyroidal extension (p=0.008), lymphovascular invasion (p=0.044), presence of right paratracheal anteromedial (RPTAMLN) metastasis (p=0.001), and presence of left paratracheal metastasis (p=0.049) were statistically significant factors. However, in the multivariate analysis, only the presence of RPTAMLN was determined to be a significant variable (p=0.035).
Conclusion: In patients undergoing surgery for PTC, the risk of metastasis in the RPTPLLN should be considered higher when there is metastasis in the RPTAMLN. We believe that formal dissection of the RPTLN should be considered for optimal evaluation in patients with tumors in the right lobe where central dissection is planned. Posterolateral dissection(PLD) should be routinely performed in the presence of clinical lymph nodes in the RPTAMLN. When a decision cannot be made, PLD may not be performed if the anteromedial tissue is examined with frozen pathology and the result is negative.

Papiller Tiroid Kanserinde Sað Paratrakeal Posterolateral Lenf Bezi Metastazý Ýçin Risk Faktörleri

Giriþ: Papiller tiroid kanseri (PTK) insidansý giderek artmakta olup ameliyat sonrasý iyi seyreden saðkalým süreleri nedeniyle yapýlacak ameliyatýn geniþliði iyi belirlenmeli ve operasyon sýrasýnda geliþebilecek komplikasyonlardan kaçýnýlmalýdýr. Rekürren laringeal sinirin (RLS) sað ve sol boyun taraflarýndaki anatomik seyrinden dolayý sað paratrakeal lenf bezleri anteromedial ve posterolateral olarak ikiye ayrýlmakta ve posterolateral lenf bezleri RLS ile yakýn bir komþuluk halinde bulunmaktadýr. Bu komplikasyon riski nedeniyle bu çalýþmada PTK’da oluþabilen sað paratrakeal posterolateral lenf bezi (SPTPLLB) metastazý için risk faktörlerini belirlemeyi amaçladýk.
Gereç ve Yöntem: 2013-2022 yýllarý arasýnda tiroid bezi sað lobda PTK mevcudiyeti nedeniyle santral boyun diseksiyonu veya santral ve lateral boyun diseksiyonu yapýlmýþ olan hastalar çalýþmaya dahil edildi. Tanýmlayýcý verilerle beraber preoperatif görüntüleme bulgularý ve postoperatif patoloji bulgularý retrospektif olarak deðerlendirildi.
Bulgular: Kriterlere uyan 55 hastanýn verileri istatistiksel olarak deðerlendirildi. Hastalarýn 24’ü (%43.6) erkek, 31’i (%56.4) kadýndý. Yaþ ortalamalarý 47.9±17.5(16-81)’du. Ortalama tümör çapý 2.17±1.43(0.4-7.0) cm’di. Hastalarýn 13’ünde (%23.6) SPTPLB metastazý izlendi. Tek deðiþkenli analizde ekstratiroideal yayýlým (p=0.008), lenfovasküler invazyon (p=0.044), sað paratrakeal anteromedial lenf bezi (SPTAMLB) metastaz varlýðý (p=0.001) ve sol paratrakeal metastaz (p=0.049) varlýðý istatistiksel olarak anlamlý faktörler olarak belirlendi. Yapýlan çok deðiþkenli analizde yalnýzca sað paratrakeal anteromedial bölgede lenf bezi metastazý olmasý anlamlý deðiþken olarak belirlendi(p=0.035).
Sonuç: PTK nedeniyle opere olan hastalarda intraoperatif deðerlendirme sýrasýnda, SPTPLLB’inde metastaz olma riskinin SPTAMLB’inde metastaz olmasýyla beraber arttýðý göz önünde bulundurulmalýdýr. Santral diseksiyon planlanan sað lobda tümörü olan hastalarda sað paratrakeal diseksiyonun formal yapýlmasýnýn optimal deðerlendirme açýsýndan uygun olacaðý kanaatindeyiz. SPTAMLB varlýðýnda posterolateral diseksiyon rutin uygulanmalýdýr. Karar verilemediðinde anteromedial doku frozen patoloji ile incelenerek negatif sonuçlanmasý durumunda posterolateral diseksiyon uygulanmayabilir. (SETB-2024-09-153)