Endocrinol Metab (Seoul). 2024;39(3):450-460.

Diagnostic Accuracy of Preoperative Radiologic Findings in Papillary Thyroid Microcarcinoma: Discrepancies with the Postoperative Pathologic Diagnosis and Implications for Clinical Outcomes.

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제1저자 이영 · 교신저자 조선욱

PMID 38798239 PMC11220223 DOI 10.3803/EnM.2023.1872 IF 5.1 내분비대사내과

소속 (7)

Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Department of Internal Medicine, Uijeongbu Eulji Medical Center, Eulji University, Uijeongbu, Korea.
Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.
Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Korea.

Abstract

BACKGRUOUND The diagnostic accuracy of preoperative radiologic findings in predicting the tumor characteristics and clinical outcomes of papillary thyroid microcarcinoma (PTMC) was evaluated across all risk groups.

METHODS In total, 939 PTMC patients, comprising both low-risk and non-low-risk groups, who underwent surgery were enrolled. The preoperative tumor size and lymph node metastasis (LNM) were evaluated by ultrasonography within 6 months before surgery and compared with the postoperative pathologic findings. Discrepancies between the preoperative and postoperative tumor sizes were analyzed, and clinical outcomes were assessed.

RESULTS The agreement rate between radiological and pathological tumor size was approximately 60%. Significant discrepancies were noted, including an increase in tumor size in 24.3% of cases. Notably, in 10.8% of patients, the postoperative tumor size exceeded 1 cm, despite being initially classified as 0.5 to 1.0 cm based on preoperative imaging. A postoperative tumor size >1 cm was associated with aggressive pathologic factors such as multiplicity, microscopic extrathyroidal extension, and LNM, as well as a higher risk of distant metastasis. In 30.1% of patients, LNM was diagnosed after surgery despite not being suspected before the procedure. This group was characterized by smaller metastatic foci and lower risks of distant metastasis or recurrence than patients with LNM detected both before and after surgery.

CONCLUSION Among all risk groups of PTMCs, a subset showed an increase in tumor size, reaching 1 cm after surgery. These cases require special consideration due to their association with adverse clinical outcomes, including an elevated risk of distant metastasis.

Keywords

DiscrepancyLymph node metastasisPapillary thyroid microcarcinomaRadiologic diagnosisTumor size

Figures

**Fig. 1.** Discrepancies of tumor size before and after surgery in papillary thyroid microcarcinoma. The difference between preoperative radiological and postoperative pathological tumor sizes is denoted as the “difference (D)” value. Agreement in tumor size was defined as a D value between –20% and 20%. D ≤–20% was categorized as a decrease in size, whereas D ≥20% were categorized as an increase in size. (A) Correlations between preoperative and postoperative tumor size. (B) Sankey diagram for differences in tumor size before and after surgery.

**Fig. 2.** Representative cases of the discrepancy between tumor size before and after surgery. (A, B) The first case involves a 55-year-old woman with papillary thyroid microcarcinoma (PTMC). An ultrasonographic (USG) image of the right thyroid gland reveals an ill-defined, irregular-shaped lesion that was initially evaluated as two separate nodules. The nodules measured 0.75 cm (A) and 0.47 cm (B). However, after surgery, it was confirmed that these nodules were actually part of a single tumor with a size of 1.9 cm. (C) The second case involves a 56-year-old woman with PTMC. A thyroid USG image shows a nodule with dense rim calcification, measured at 0.67 cm. However, postsurgery examination revealed a pathologic papillary thyroid carcinoma measuring 1.3 cm.

**Fig. 3.** Comparisons of survival outcomes based on tumor size and lymph node metastasis (LNM) in postoperative diagnosis. (A, B) Survival outcomes in relation to a tumor size of 1 cm based on the postoperative pathological measurement. Kaplan-Meier curves were utilized to analyze distant metastasis-free survival (A) and recurrence-free survival (B). (C, D) Survival outcomes between patients with LNM diagnosed both preoperatively and postoperatively (pre-post LNM), patients with LNM detected only at the time of postoperative evaluation (post-only LNM), and those without LNM detected postoperatively (no LNM). Kaplan-Meier curves were utilized to analyze distant metastasis-free survival (C) and recurrence-free survival (D). Post-T, postoperative tumor.

그림 출처: PubMed Central 공개 논문 (PMC11220223)

Conflict of interest statement

CONFLICTS OF INTEREST . Sun Wook Cho is the deputy editor of the journal. However, she was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.

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