Subcategorization of intermediate suspicion thyroid nodules based on suspicious ultrasonographic findings

Abstract

This study compared the malignancy risk of intermediate suspicion thyroid nodules according to the presence of suspicious ultrasonographic (US) findings. Methods: From January 2014 to December 2014, 299 consecutive intermediate suspicion thyroid nodules in 281 patients (mean age, 50.6±12.5 years) with final diagnoses were included in this study. Two radiologists retrospectively reviewed the US findings and subcategorized the intermediate suspicion category into nodules without suspicious findings and nodules with suspicious findings, including punctate echogenic foci, nonparallel orientation, or irregular margins. The malignancy rates were compared between the two subcategory groups. Results: Of the 299 intermediate suspicion thyroid nodules, 230 (76.9%) were subcategorized as nodules without suspicious findings and 69 (23.1%) as nodules with suspicious findings. The total malignancy rate was 33.4% (100/299) and the malignancy rate of nodules with suspicious findings was significantly higher than that of nodules without suspicious findings (47.8% vs. 29.1%, P=0.004). In nodules with suspicious findings, the most common suspicious finding was punctate echogenic foci (48/82, 58.5%) followed by nonparallel orientation (22/82, 26.8%) and irregular margins (12/82, 14.6%). Thirteen nodules had two suspicious findings simultaneously. A linearly increasing trend in the malignancy rate was observed according to the number of suspicious US findings (P for trend=0.001). Conclusion: Intermediate suspicion thyroid nodules with suspicious findings showed a higher malignancy rate than those without suspicious findings. Further management guidelines for nodules with suspicious findings should differ from guidelines for nodules without suspicious findings, even in the same US category.

Malignancy risk stratification and subcategorization of K-TIRADS intermediate suspicion thyroid nodules: a retrospective multicenter study

“…A recent study from a single institution [ 7 ] reported a higher malignancy rate in K-TIRADS 4 nodules with suspicious findings (subgroup 2 nodules) compared to those without suspicious findings (subgroup 1 nodules). This finding contrasts with the results of the present study and previous research, which indicated similar malignancy rates between the two subgroups of K-TIRADS 4 nodules [ 11 , 25 , 26 ].…”

“…However, the US features that increase the risk of malignancy in K-TIRADS 4 nodules have been seldom explored. Two studies have investigated the risk stratification and subcategorization of K-TIRADS 4 nodules based on US characteristics, but their findings are inconsistent [ 6 , 7 ]. There is a need to establish US criteria for risk stratification of K-TIRADS 4 nodules to provide useful information for making optimized biopsy decisions.…”

Subdivision of intermediate suspicion, the 2021 K-TIRADS, and category III, indeterminate cytology, the 2017 TBSRTC, 2nd edition, in thyroidology: let bygones be bygones?

“…We have read with great respect the research article titled "Subcategorization of intermediate suspicion thyroid nodules based on suspicious ultrasonographic findings." This high-quality research appears to necessitate the subcategorization of category 4 (intermediate suspicion) according to the 2021 Korean Thyroid Imaging Reporting and Data System (K-TIRADS), based on suspicious ultrasound (US) findings [ 5 , 6 ]. We believe that Kim et al's [ 5 ] emphasis on the subdivision of "intermediate suspicion" is a significant and vital issue in the field of thyroidology, as published in Volume 42 of Ultrasonography .…”

“…The saying "let bygones be bygones" may not apply here, as this issue certainly warrants further investigation. We thank Kim et al [ 5 ] for their significant study.…”

Re: Subdivision of intermediate suspicion, the 2021 K-TIRADS, and category III, indeterminate cytology, the 2017 TBSRTC, 2nd edition, in thyroidology: let bygones be bygones?

“…We were greatly interested to read the letter to the editor from Sengul and Sengul, which pertains to our recent paper on the subcategorization of intermediate suspicion thyroid nodules, based on suspicious ultrasonographic (US) findings [ 1 ].…”