Lymphatic Invasion in Bethesda VI Papillary Thyroid Microcarcinomas: A Single-Center Retrospective Analysis

Dalcı K., AYDOĞAN B.

Çukurova Anestezi ve Cerrahi Bilimler Dergisi, cilt.9, sa.1, ss.115-119, 2026 (TRDizin)

Özet

Aim: Although small size in papillary thyroid microcarcinomas is generally associated with low risk, it may not reflect the biological behavior of the tumor. In this study, the effect of lymphatic invasion on metastatic risk and the metastatic characteristics of microcarcinomas with lymphatic invasion compared to macrocarcinomas were evaluated in a cohort with Bethesda VI diagnosis. Methods: A total of 116 patients with Bethesda VI cytology were categorized into papillary microcarcinoma (n=35) and papillary macrocarcinoma (n=81) groups. Lymphatic and vascular invasion were evaluated separately. Risk factors for central lymph node metastasis and inter-group metastatic burden were compared. Results: Vascular invasion was significantly more frequent in papillary macrocarcinomas (p=0.035), whereas lym- phatic invasion rates were similar between the groups (p=0.385). In the papillary microcarcinoma group undergo- ing lymph node dissection, a significant association was detected between the presence of lymphatic invasion and central metastasis (p<0.001). Tumor size and multifocality were found to be non-significant in predicting metas- tasis. In the analysis performed, no difference was observed between the number of metastatic lymph nodes in lymphatic invasion-positive papillary microcarcinomas and macrocarcinomas (5.2 vs 4.9; p=0.597). A metastatic case with a 5 mm tumor size supported the independence of the aggressive phenotype from tumor size. Conclusions: Since the presence of lymphatic invasion in papillary microcarcinomas suggests that the tumor’s metastatic potential may be elevated to a level similar to that of macrocarcinomas, considering a more cautious strategy in the clinical management of these cases may be beneficial. However, due to the limited sample size, these findings are hypothesis-generating rather than definitive and should be validated in larger cohorts.