Endocrine Abstracts

Introduction: Papillary thyroid microcarcinomas (PTMC) are usually detected incidentally. They occur as a result of histological/microscopic examination of a thyroid removed especially for nodular goiter. Generally, the prognosis is good. However, it has been reported that lymph node (LN) metastasis is more common especially in PTMCs with tumor size > 5mm. In this study, it was aimed to show the effect of tumor size on prognosis by comparing clinicopathological data in patients with PTMCs ≤ 5mm and > 5mm.

Material-Method: A total of 246 patients aged >18 years, who were operated at Samsun Ondokuz Mayıs University Faculty of Medicine between January 2008 and October 2021 and whose pathology was reported as PTMC, were followed for at least 30 months, were included in the study. The patients were divided into two groups. The first group included 131 patients with a tumor size of ≤ 5mm, and the second group included 115 patients with a tumor size of 5-10mm. The age, gender, performed surgical procedure, pathology results, recurrence, distant and LN metastasis, mortality, radioactive iodine (RAI) ablation and follow-up periods were recorded. The results were compared between the two groups.

Results: When the groups were compared in terms of pathology results, multifocality (P=0.009), parenchymal invasion (P=0.008), calcification (P=0.001), lymphatic invasion (P=0.002) and presence of metastatic LN (P<0.001) were found to be statistically more significant in those with tumor size > 5mm. RAI ablation therapy was significantly higher in the group with tumor size > 5mm (P<0.001). There was no statistically significant difference between the two groups in terms of follow-up time and recurrence. Distant metastasis and disease-related death were not detected in any of them. There was a significant difference between the groups in terms of tumor type (P=0.049). Tall cell variant was more common in tumor size > 5mm.

Discussion and conclusion: Our findings show that recurrence rates were similar in patients with PTMCs ≤ 5mm and >5mm, and there was no disease-related mortality in either group. However, in the group with tumour size > 5 mm, predictive values which may be associated with tumor aggressiveness as multifocality, parenchymal invasion, calcification, lymphatic invasion, LN metastasis and the tall cell variant were found to be significantly higher. We conclude that patients with > 5mm PTMK, having these positive predictive factors, should be managed more carefully.