Atypical Thyroid Cancers on Sonography

International Expert Consensus on US Lexicon for Thyroid Nodules

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.

Histopathological correlation of punctate echogenic foci on ultrasonography in papillary thyroid carcinoma

PURPOSE

To investigate the pathological entities of punctate echogenic foci (PEF) by correlating PEF with histopathological features of papillary thyroid carcinoma (PTC).

METHODS

This study included 121 consecutive patients who had undergone thyroidectomy for PTC. The inclusion criterion was entire tumor resection with a 3-mm thickness for histopathological examination. We assessed the presence and number (<5 or ≥5) of PEF defined as punctate hyperechoic foci within the solid component of nodules. All surgical tumor specimens were retrospectively reviewed for the presence of microcalcifications, including the psammomatous calcification, coarse microcalcification, and micro-ossification, and inspissated colloid.

RESULTS

PEF were detected in 71 (58.7%) PTCs. Psammomatous calcifications, coarse microcalcifications, and inspissated colloids were more frequently found in PTCs with PEF than in those without (74.6%, 42.3%, and 46.5%, respectively, p ≤ 0.024). Any type of microcalcification was found in 90.1% of PTCs with PEF. Psammomatous calcifications, coarse microcalcifications, and inspissated colloids were independently associated with PEF (p ≤ 0.012). Psammomatous calcifications were found in all PTCs with a high number (≥5) of PEF.

CONCLUSION

Microcalcifications were found in most PTCs with PEF and psammomatous calcification was the main pathological entity of PEF in PTC. Our study validates reliability of PEF as a predictor of microcalcifications in PTC.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Analysis of Malignant Thyroid Nodules That Do Not Meet ACR TI-RADS Criteria for Fine-Needle Aspiration

OBJECTIVE. Compared with other guidelines, the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) has decreased the number of nodules for which fine-needle aspiration is recommended. The purpose of this study was to evaluate the characteristics of malignant nodules that would not be biopsied when the ACR TI-RADS recommendations are followed. MATERIALS AND METHODS. We retrospectively reviewed a total of 3422 thyroid nodules for which a definitive cytologic diagnosis, a definitive histologic diagnosis, or both diagnoses as well as diagnostic ultrasound (US) examinations were available. All nodules were categorized using the ACR TI-RADS, and they were divided into three groups according to the recommendation received: fine-needle aspiration (group 1), follow-up US examination (group 2), or no further evaluation (group 3). RESULTS. Of the 3422 nodules, 352 were malignant. Of these, 240 nodules were assigned to group 1, whereas 72 were assigned to group 2 and 40 were included in group 3. Sixteen of the 40 malignant nodules in group 3 were 1 cm or larger, and, on the basis of analysis of the sonographic features described in the ACR TI-RADS, these nodules were classified as having one of five ACR TI-RADS risk levels (TR1-TR5), with one nodule classified as a TR1 nodule, eight as TR2 nodules, and seven as TR3 nodules. If the current recommendation of no follow-up for TR2 nodules was changed to follow-up for nodules 2.5 cm or larger, seven additional malignant nodules and 316 additional benign nodules would receive a recommendation for follow-up. If the current size threshold (1.5 cm) used to recommend US follow-up for TR3 nodules was decreased to 1.0 cm, seven additional malignant nodules and 118 additional benign nodules would receive a recommendation for follow-up. CONCLUSION. With use of the ACR TI-RADS, most malignant nodules that would not be biopsied would undergo US follow-up, would be smaller than 1 cm, or would both undergo US follow-up and be smaller than 1 cm. Adjusting size thresholds to decrease the number of missed malignant nodules that are 1 cm or larger would result in a substantial increase in the number of benign nodules undergoing follow-up.

Effect of Decreasing the ACR TI-RADS Point Assignment for Punctate Echogenic Foci When They Occur in Mixed Solid and Cystic Thyroid Nodules

OBJECTIVE. Using the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS), this study sought to determine whether decreasing the point assignment for punctate echogenic foci in mixed solid and cystic nodules would reduce the number of benign mixed solid and cystic nodules that were biopsied and would not substantially increase the number of missed mixed carcinomas MATERIALS AND METHODS. A multiinstitutional database of 3422 pathologically proven thyroid nodules was evaluated to identify all mixed solid and cystic nodules with punctate echogenic foci. We determined the numbers of mixed benign and malignant nodules that would receive ACR TI-RADS recommendations of fine-needle aspiration, follow-up, and no further evaluation if the points assigned to punctate echogenic foci were changed from 3 points to 1 or 2 points. RESULTS. A total of 287 mixed nodules were adequately characterized for evaluation. When the number of points assigned to punctate echogenic foci was changed from 3 points to 1 point, the point categories changed for 198 mixed nodules. Seven carcinomas would not undergo biopsy, but six of those seven would receive follow-up, and 44 benign nodules would not undergo biopsy. When 2 points were assigned to punctate echogenic foci, the point categories changed for 66 mixed nodules. Three carcinomas would not undergo biopsy, but all three of these would receive follow-up, and eight benign nodules would not undergo biopsy. CONCLUSION. Consideration should be given to decreasing the number of points assigned to punctate echogenic foci in mixed solid and cystic thyroid nodules, given the substantial decrease in the number of benign nodules requiring biopsy and the recommendation of follow-up for any carcinoma 1 cm or larger that did not undergo biopsy.

2020 Chinese guidelines for ultrasound malignancy risk stratification of thyroid nodules: the C-TIRADS

Thyroid nodules are very common all over the world, and China is no exception. Ultrasound plays an important role in determining the risk stratification of thyroid nodules, which is critical for clinical management of thyroid nodules. For the past few years, many versions of TIRADS (Thyroid Imaging Reporting and Data System) have been put forward by several institutions with the aim to identify whether nodules require fine-needle biopsy or ultrasound follow-up. However, no version of TIRADS has been widely adopted worldwide till date. In China, as many as ten versions of TIRADS have been used in different hospitals nationwide, causing a lot of confusion. With the support of the Superficial Organ and Vascular Ultrasound Group of the Society of Ultrasound in Medicine of the Chinese Medical Association, the Chinese-TIRADS that is in line with China's national conditions and medical status was established based on literature review, expert consensus, and multicenter data provided by the Chinese Artificial Intelligence Alliance for Thyroid and Breast Ultrasound.

Malignancy risk of thyroid nodules with nonshadowing echogenic foci

Purpose

This study was conducted to determine the malignancy risk and diagnostic value of various types of nonshadowing echogenic foci (NEF) in the risk stratification of thyroid nodules.

Methods

A total of 1,018 consecutive thyroid nodules (≥1 cm) with final diagnoses were included. The presence of NEF was determined and types of NEF were classified according to the presence of a comet tail artifact (CTA), location, and size through a prospective evaluation. The associations with malignancy, malignancy risk, and diagnostic value of various types of NEF were assessed.

Results

Intrasolid punctate NEF without CTA was the only type of NEF that was an independent predictor of malignancy (P<0.001). The malignancy risk of intrasolid punctate NEF without CTA was substantially higher in solid hypoechoic nodules than in isoechoic or nonsolid nodules (71.3% vs. 9.2%, P<0.001). In solid hypoechoic nodules, slightly increased sensitivity (70.8% vs. 67.9%) for malignancy and a similar malignancy risk (71.4% vs. 71.3%) were observed for intrasolid punctate NEF (with or without CTA) and intrasolid punctate NEF without CTA, respectively. NEF with CTA at the margin of the cystic component was not associated with malignancy or benignity in nonsolid nodules (P>0.05).

Conclusion

Intrasolid punctate NEF without CTA was the only independent predictor of malignancy. However, solid hypoechoic nodules with intrasolid punctate NEF should be classified as high-suspicion nodules regardless of coexisting CTA. Other types of NEF had no added value for detecting malignancy compared to intrasolid punctate NEF without CTA.

Thyroid Radiology Practice: Diagnosis and Interventional Treatment of Patients with Thyroid Nodules

갑상선 영상의학 진료란 갑상선 질환 환자를 영상의학적 방법을 활용하여 질병 진단과 중재적 치료를 하는 의료 행위로 정의될 수 있으며 주요 진료 대상은 갑상선 결절 질환 환자들이다. 갑상선 결절의 진단은 일차적으로 초음파 영상진단과 생검에 의해서 이루어지고 결절의 치료는 비수술적 중재적 치료와 갑상선절제술이다. 갑상선 낭종 혹은 낭성우세 양성 결절에서는 에탄올절제술이 일차적 치료법이고 고주파절제술은 고형 혹은 고형우세 양성 결절과 갑상선 재발암 치료에 적용되고 있다. 갑상선 영상의학 진료는 갑상선 결절 질환 환자의 진단 및 비수술적 치료의 대부분을 담당하는 중요한 임상적 역할을 가지고 있으며, 적절한 환자 진료를 위해서는 표준적 진료 지침에 근거하여 진료가 수행되어야 한다. 환자에게 최적의 갑상선 영상의학 진료를 제공하기 위해서는 영상의학과 외래에서 환자를 진료하는 것이 바람직하며 외래 중심의 갑상선 영상의학 진료를 확대하도록 함께 노력해야 할 시점이다.

The levels of NF-κB p50 and NF-κB p65 play a role in thyroid carcinoma malignancy in vivo

Background To investigate the relationship between the levels of nuclear factor (NF)-κB p50 and NF-κB p65 and tumour characteristics in patients with thyroid carcinoma. Methods This prospective study enrolled consecutive patients with thyroid carcinoma. Tumour samples were collected and the levels of NF-κB p50 and NF-κB p65 protein and mRNA were measured using immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Results A total of 73 patients with thyroid carcinoma were included in the study (20 males; 53 females; mean ± SD age, 44.8 ± 12.7 years, range, 18-76 years). There were no significant differences in sex, age and pathological type between the NF-κB p50 positive group and the NF-κB p50 negative group, but tumour diameter and lymph node metastasis were significantly higher in the NF-κB p50 positive group compared with the NF-κB p50 negative group. Similar findings were observed for NF-κB p65. The levels of NF-κB p50 were positively correlated with NF-κB p65 in samples of thyroid carcinoma ( rs = 0.653). Conclusion The levels of NF-κB p50 and NF-κB p65 in samples of thyroid carcinoma were positively associated with tumour diameter and the presence of lymph node metastasis.

Echogenic foci with comet-tail artifact in resected thyroid nodules: Not an absolute predictor of benign disease

The purpose of this study was to evaluate the frequency of echogenic foci with comet-tail artifact in histologically proven thyroid nodules, and to determine the types of echogenic foci with comet-tail artifact that are associated with malignancy. We retrospectively analyzed the sonographic findings of echogenic foci with comet-tail artifact, present in thyroid nodules in 63 patients who underwent surgery for thyroid nodules at our institution between January 2016 and September 2016. The sonographic findings (appearance and background of echogenic foci, shape of comet-tail artifact) in benign and malignant nodules were compared. Seventy-one (7.4%) nodules with ultrasound finding of echogenic foci with comet-tail artifact were encountered in 962 thyroid nodules of 556 patients; 25 of these were benign, and 46 were malignant. Among the echogenic foci with comet-tail artifact categories, those (11/11, 100%) freely distributed in cystic components were all in benign nodules, whereas those (48/67, 71.6%) any part of echogenic foci or comet-tail artifact associated with solid components, were more common in malignant nodules (P < 0.001). There was no statistically significant difference in the appearance of echogenic foci and the shape of comet-tail between the benign and malignant nodules (P = 0.139, P = 0.626, respectively). Echogenic foci with comet-tail artifact freely distributed in cystic component may predict a benign nodule; those associated with solid components cannot be considered a benign finding.