Thyroid ultrasonography. Part 2: nodules

Explore the diagnostic performance of 2020 Chinese Thyroid Imaging Reporting and Data Systems by comparing with the 2017 ACR-TIRADS guidelines: a single-center study

OBJECTIVE

To compare the diagnostic efficacy of the Chinese Thyroid Imaging Reporting and Data Systems (C-TIRADS) with the well-accepted ACR-TIRADS guidelines in identifying benign from malignant thyroid nodules.

METHODS

A total of 2064 nodules were collected from 1627 patients undergoing thyroid ultrasonography in our center between October 2019 and November 2021. Nodules were divided into two groups: "≥1 cm" and "<1 cm". Ultrasound features of each nodule were observed and recorded by two physicians with more than 15 years of experience and classified according to the ACR-TIRADS and C-TIRADS guidelines, respectively.

RESULTS

The area under the curve of the ACR-TIRADS guideline was higher than that of the C-TIRADS guideline (0.922, P = 0.017), the specificity and positive predictive value of the C-TIRADS guideline were higher (81.64%, 88.72%, all P < 0.05), which was more significant in the subgroup of nodules <1 cm (P = 0.001). In addition, there was no statistical difference between the two guidelines in the diagnostic efficacy indicators for nodules ≥1 cm. The ACR-TIRADS effectively reduced unnecessary biopsies compared with the C-TIRADS (P < 0.05).

CONCLUSIONS

There was high agreement between the two guidelines for the diagnosis of thyroid nodules, C-TIRADS guidelines had a higher specificity and simplicity while were inferior to the ACR-TIRADS guidelines in terms of reducing the number of biopsies.

Primary thyroid teratoma in adults: A case report and systematic review of the literature

Extragonadal germ cell tumors are uncommon in adults and only 2-5% of teratomas develop in extragonadal sites. Primary thyroid teratomas represent <0.1% of all primary thyroid gland neoplasms. In the present report, a case of primary thyroid teratoma in a 65-year-old female is described. Furthermore, the current literature regarding patients who were diagnosed with primary thyroid teratoma and underwent surgical resection was systematically reviewed. A total of 15 studies of 27 patients (age range, 17-65 years). Growing mass or neck swelling were the primary symptoms in 14 patients (51.8%). Only one (5.5%) patient was preoperatively diagnosed with malignant thyroid teratoma. All patients underwent thyroidectomy, but 6 cases had more advanced surgery, including lymph node dissection. A total of 12 patients received a combination of adjuvant chemoradiation postoperatively, 10 (45.4%) patients reported recurrence of disease and 8 (29.6%) were postoperatively diagnosed with distant metastases. A total of 9 (39.1%) patients died due to progression of the disease. In conclusion, primary thyroid teratomas are rare and difficult to diagnose preoperatively. In particular, malignant cases are very aggressive tumors with a considerably poor prognosis, even after surgical resection combined with adjuvant chemoradiation.

Effect of Chinese herbal medicine for patients with benign thyroid nodules in adults: A protocol for systematic review and meta-analysis

BACKGROUND

Thyroid nodules (TN) are discrete lesions within the thyroid gland and are a common clinical problem detected in 19% to 68% of people. TN are more common as age increases and occur more frequently in women. TN can cause pressure symptoms, cosmetic complaints, and thyroid dysfunction. Treatment for benign thyroid nodules includes thyroid hormone therapy, surgery, radioiodine treatment, percutaneous ethanol injection therapy, and laser or radiofrequency treatment to shrink nodules. In China and many other countries, doctors use Chinese herbal medicines (CHM) to treat TN. However, systematic review and meta-analysis has not been found to assess the effects and safety of CHM in curing TN at present. Hence, the systematic review is conducted to scientifically and methodically evaluate the value of its effectiveness and safety of CHM on TN.

METHODS

Literatures related to CHM for TN from the establishment of the database to November 2020 will be retrieved from the following databases: PubMed, Excerpta Medica Database (EMBASE), MEDLINE, Web of Science, Cochrane Library, SpringerLink, WHO International Clinical Trials Registry Platform (ICTRP), Wanfang Database, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), and Chinese Scientific Journal Database (VIP). There are no language restrictions for retrieving literatures. Case reports, animal studies, editorials, expert opinions, reviews without original data, and studies on pediatric population were excluded. Eligible randomized clinical trials (RCTs) evaluating the effectiveness and safety of CHM in TN patients will be put in the study including nodule volume reduction ≥50%, pressure symptoms, cosmetic complaints, quality of life, and adverse events. By scanning the titles, abstracts and full texts, 2 reviewers will independently select studies, extract data, and assess the quality of study. Meta-analysis of RCTs will be conducted using Review Manager 5.1 software. The results will be presented as risk ratio for dichotomous data, and standardized or weighted mean difference for continuous data.

RESULT

This study will provide high-quality available evidence for the treatment of TN with CHM based on nodule volume reduction ≥50%, pressure symptoms, cosmetic complaints, quality of life, and adverse events.

CONCLUSION

The systematic review will to evaluate the efficacy of CHM in treating benign thyroid nodules in adults and provide evidence for clinicians.

INPLASY REGISTRATION NUMBER

INPLASY2020120093.

A case report of a giant mature teratoma of the thyroid gland in a young girl

RATIONALE

Teratomas are extremely rare in the thyroid gland. A cervical teratoma presenting as a cystic or mixed thyroid lesion can be easily confused with a thyroglossal duct cyst. It is difficult for pediatricians to differentiate between these 2 types of lesions.

PATIENTS CONCERNS

A 2-year-old girl who presented a growing thyroid mass for 14 months showed a mass in her left thyroid lobe under contrast-enhanced computed tomography (CT).

DIAGNOSIS AND INTERVENTIONS

Ultrasonography found a mass of 5 × 3.5 cm within the left lobe of the thyroid gland, and the sonogram revealed areas with echo-free and mixed-echo patterns. There was no accumulation of technetium-99m pertechnetate on the thyroid scintigraphy (cold thyroid nodule). CT scan showed a mass (5.0 × 3.0 × 2.5 cm in size) that extended from the left thyroid lobe to the anterior mediastinum with no evident enhancement and clear margins that contained calcifications. Complete excision without intraoperative capsule disruption was achieved. Histologically, the thyroid mass was diagnosed as a mature teratoma.

OUTCOMES

The postoperative course was uneventful after follow-ups for 2 years, and the patient had no inflammatory signs or evidence of recurrence.

LESSONS

Thyroid teratoma is rare in infants and is usually benign; however, some thyroid teratomas are malignant and inclined to relapse. The authors emphasize that thyroid teratomas in children should be included in the differential diagnosis of cystic lesions located in the head and neck area. Complete resection is essential for good outcomes. In addition, long-term follow-ups are warranted to follow the complications of the malignant or recurrent disease.

Significance of contrast-enhanced ultrasonography in differential diagnosis of thyroid nodules

The present study was aimed to compare the application values between 2-dimensional color Doppler ultrasonography (2DUS) and contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of thyroid malignant nodules.A total of 124 patients suspectedly diagnosed with malignant thyroid nodules under conventional gray-scale ultrasonography were recruited in this study. All enrolled patients were examined by both 2DUS and CEUS.A total of 153 nodules (94.44%) and 45 cases (90.00%) with malignant nodules were detected by the CEUS. No significant differences were noted in nodule detection rates between 2DUS and CEUS (χ = 1.170, P = .279; χ = 0.796, P = .372). The aspect ratio, microcalcification, internal echo, borderline, Vmax, resistance index, and total scores of malignant nodules were higher than those of benign nodules (all P < .05) when diagnosed by 2DUS. The peripheral/internal enhancement time, peak intensity, local enhancement, ring enhancement, and total scores of malignant nodules were significantly higher compared with those of benign nodules (all P < .05) by CEUS. Total score of malignant nodules diagnosed by 2DUS was approximately 3.5 and 2.3 points for CEUS. The diagnostic accuracy of 2DUS as observed by area under the curve was 0.821 with the cut-off value of 3.9, the sensitivity was 82.5%, and the specificity was 85.6%. The diagnostic accuracy of CEUS was 0.862 with the cut-off value of 2.8, the sensitivity was 86.7%, and the specificity was 91.3%.Both 2DUS and CEUS are worthy of application values in the differential diagnosis from benign to malignant thyroid nodules.

Shear wave elastography and contrast-enhanced ultrasonography in the diagnosis of thyroid malignant nodules

The aim of the present study was to evaluate the value of shear wave elastography (SWE) and contrast-enhanced ultrasonography (CEUS) in the diagnosis of thyroid malignant nodules. A total of 253 patients with 319 thyroid nodules were subjected to two-dimensional ultrasound (2DUS) and CEUS examinations prior to thyroidectomy between March, 2014 and December, 2015. Young's modulus value for each nodule on 2DUS and CEUS images were recorded. The sensitivity, specificity and accuracy of 2DUS, SWE and CEUS in the diagnosis of thyroid malignant nodules were assessed. The results demonstrated that, of the 319 nodules that were pathologically confirmed, 183 were malignant and 136 were benign. The area under the receiver operating characteristic curve as a result of SWE diagnosis was 0.77. When the threshold of the Young's modulus value was ≥27.65 kPa in the diagnosis of malignant thyroid nodules, SWE exhibited a sensitivity of 84.55% (115/136), a specificity of 84.15% (154/183) and an accuracy of 84.32% (269/319). US contrast imaging of malignant thyroid nodules revealed a major tendency for early hypoenhancement and hypoenhancement. CEUS exhibited a sensitivity of 87.5% (119/136), a specificity of 86.33% (158/183) and an accuracy of 86.83% (277/319) in the diagnosis of malignant thyroid nodules. Compared with 2DUS, SWE, CEUS and their combined use exhibited statistically significant differences in the diagnosis of thyroid malignant nodules in terms of sensitivity, specificity and accuracy (χ²=9.220,15.310 and 40.296, respectively; P=0.000); SWE or CEUS did not differ significantly in the diagnosis of thyroid malignant nodules in terms of sensitivity, specificity or accuracy (χ²=0.737;P=0.542); Compared with the use of SWE or CEUS alone, their combination exhibited statistically significant differences in the diagnosis of malignant thyroid nodules in terms of sensitivity, specificity and accuracy (χ²=12.264 and 6.939, respectively; P=0.000,0.005). In conclusion, the high accuracy of the combined use of SWE and CEUS in the diagnosis of malignant thyroid nodules is of great clinical value.

Is there a real diagnostic impact of elastosonography and contrast-enhanced ultrasonography in the management of thyroid nodules?

Ultrasonography (US) and the new applications US elastography (USE) and contrast-enhanced US (CEUS) are used in the screening of thyroid nodules, for which fine-needle aspiration biopsy (FNAB) is the best single diagnostic test. The aim of the study was to compare the sensitivity, specificity, positive predictive value (PPV), and accuracy of the four examinations in nodules with cytological and histological diagnoses. The study used data from US, FNAB, USE (elasticity (ELX 2/1) index), and CEUS (Peak index and time to peak (TTP) index) evaluated in 73 thyroid nodules in 63 consecutive patients likely to undergo surgery. Cytological-histological correlation was available for 38 nodules. No correlation emerged between nodule size and cytological results. A significant (P=0.03) positive correlation between cumulative US findings and cytological results was found. In addition, significant correlations between cumulative US findings and cytology (P=0.02) and between cumulative US findings and histology (P<0.0001) were found. US showed the best specificity and PPV, and FNAB the best sensitivity. There was no significant difference in the ELX 2/1 index, Peak index, or TTP index among nodules subdivided according to cytological scores. No significant correlation was found between ELX 2/1 index, Peak index, and TTP index, on the one hand, and nodule size, US cumulative findings, cytology, and histology on the other hand. The sensitivity of the ELX 2/1 index was high, but its specificity was very low. The accuracy and PPV of USE were lower than those of the other procedures. Only the correlation between Peak index and cumulative US findings reached a value close to significance. Our ultimate aim is to minimise unnecessary thyroidectomy. US and FNAB continue to play a central diagnostic role. The use of a US score showed high specificity and PPV. The specificity of FNAB was low in this selected series because of the numbers of indeterminate cytological responses. USE and CEUS are innovative techniques that need to be standardized. The ELX 2/1 index, Peak index, and TTP index seem to be unrelated to histology. The best statistical data on USE and CEUS concerned their sensitivity and PPV, respectively. At present, USE and CEUS are too time-consuming and of limited utility in selecting patients for surgery.

Benign teratoma of the thyroid gland

Although pathology reports of thyroid tissue in ovarian teratomas are abundant, benign teratomas of the thyroid are extremely rare in adolescents and adults. Therefore, their clinical characteristics are still not well characterized. We report a case of a 54-year-old woman with a growing mass in her neck. Left lobectomy of the thyroid revealed it to be a benign thyroid teratoma composed of tissues from all three germ layers. Preoperative evaluations included thyroid ultrasonography (US), ultrasound-guided fine needle aspiration cytology (FNAC), and computed tomography (CT) of the neck. A 4.7-cm, well defined, predominantly hypoechoic mass intermingled with hyperechoic internal lesions, was observed in the inferior portion of the left thyroid lobe with substernal extension on US. The posterior extent of the nodule was not visualized due to deep attenuation of the echo. US-guided FNAC failed to reveal any thyroid follicular cells, but suggested a benign cystic tumor. Neck CT hinted at the diagnosis of teratoma because the mass contained large amounts of fat, and the margin was well defined. Extrathyroidal extension and cervical lymphadenopathy were not seen. She underwent left thyroid lobectomy, and histologic examination confirmed benign thyroid teratoma. To the best of our knowledge, this is the first case report of benign thyroid teratoma in Korea.