[Metastatic adenopathy from a thyroid microcarcinoma: final diagnosis of a presumed paraganglioma]

Correlation between Ultrasonographic Appearance of Papillary Thyroid Microcarcinoma and BRAF V600E Mutation

The study was conducted to investigate the correlation between the ultrasonographic appearance of a thyroid nodule and the BRAF V600E mutation. Patients with thyroid nodules (n = 186), for which BRAF V600E testing and cytopathology analysis were performed, and who underwent subsequent surgery for nodule resection were enrolled in this study. For each patient, color Doppler ultrasonography was performed to observe the variables of the nodules. The nodules were then characterized using the thyroid imaging reporting and data system classification TI-RADS. Furthermore, the ultrasonographic appearance of the control group, encompassing patients with nodular thyroid goiters, and the case group, encompassing patients with papillary thyroid microcarcinoma (PTMC), was statically analyzed. Similarly, a statistical analysis of the ultrasonographic appearance of the BRAF V600E-positive and BRAF V600E-negative subgroups was also performed. The accuracy was significantly different for the corresponding values when color Doppler ultrasonography, BRAF V600E testing, or cytopathology alone was used for diagnosis. There were significant differences in the ultrasonographic appearance variables between the control and case groups. Comparing with the BRAF V600E-negative subgroup of the case group, the ultrasonographic appearances of the BRAF V600E-positive subgroup showed less circumscribed and more irregularly shaped nodules, with significantly different aspect ratios of >1. The combination of BRAF V600E testing and color Doppler ultrasonography or cytopathology improved the accuracy of the PTMC diagnose. We found that the ultrasonographic appearance of thyroid nodules was related to PTMC.

Papillary Thyroid Carcinoma in Ectopic Thyroid Tissue Within a Suspected Cervical Paraganglioma

ABSTRACT

Ectopic differentiated thyroid carcinoma represents less than 1% of all thyroid carcinoma cases, which usually arises along the cervical midline, and (delving into literature) there are scarce reports of such entity in nuclear medicine imaging studies. We present a rare case of a confirmed synchronous, orthotopic, and heterotopic (in lateral ectopic thyroid tissue) differentiated thyroid carcinoma in a patient who was previously misdiagnosed as having a cervical paraganglioma, based on compatible clinical, analytical, and imagenological (both structural and functional) findings.

DNA double-strand break repair gene mutation and the risk of papillary thyroid microcarcinoma: a case-control study

Objective

To study the relationship between DNA double-strand break (DSB) repair gene mutations and the risk of papillary thyroid microcarcinoma (PTMC).

Methods

One hundred patients with PTMC or benign thyroid nodules (BTNs) at Henan Cancer Hospital were retrospectively analyzed. The DSB repair capacity of peripheral blood T lymphocytes in the two groups was assessed by flow cytometry. Data were compared using Student’s t-test to evaluate the relationship between DSB repair capacity and the risk of PTMC. Factors influencing DSB repair capacity were analyzed by multivariate logistic regression analysis. The relationship between PTMC and DSB repair capacity was analyzed by univariate analysis. Targeted next-generation DNA sequencing was applied to screen and analyze DSB repair genes related to PTMC.

Results

The DSB repair capacity was 31.30% in the PTMC group and 44.40% in the BTN group, with that of the former being significantly lower (P < 0.05). Multivariate logistic regression analysis of age, sex, obesity status, radiation and other factors showed that radiation exposure was positively correlated with reduced DSB repair capacity(OR = 3.642; 95% CI 1.484–8.935, P = 0.020). Moreover, univariate analysis showed that a reduction in DSB repair capacity was a risk factor for PTMC(OR = 2.333; 95% CI 1.027–5.300, P = 0.043).Targeted next-generation DNA sequencing was performed on the DSB repair genes discovered, and those that were mutated in association with PTMC were Rad50 and FANCA; Rad51 mutations were related to BTN.

Conclusion

Radiation exposure is positively associated with induced DSB repair gene mutations, which may cause a reduced capacity for DSB repair and eventually lead to PTMC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02032-5.

Associations of BRAF V600E, clinical pathology and imaging factors with the recurrence rate of papillary thyroid microcarcinoma

In the present study, the recurrence rate of papillary thyroid microcarcinoma (PTMC) was assessed by analyzing postoperative follow-up data of affected patients and its associations with BRAF V600E, clinical pathology and imaging factors were explored. A total of 506 patients with PTMC were selected who underwent surgery from January 2014 to March 2016. The maximal diameter of thyroid nodules was ≤1 cm and all patients who underwent BRAF V600E testing and evaluation for lymph node metastasis. Postoperatively, each patient was regularly followed up to detect recurrence. Categorical variables were comparatively analyzed using univariate Cox linear regression analysis to screen for protective and adverse factors influencing recurrence of PTMC. A stepwise Cox proportional hazards regression model analysis was performed to explore risk factors affecting recurrence. Among the 506 patients, 477 were followed up, 29 were lost to follow-up and 26 patients experienced recurrence. The 5-year recurrent rate of PTMC was 5.45%. The univariate Cox regression analysis indicated that PTMC recurrence was influenced by BRAF V600E, sex, multifocality, capsular invasion and lateral cervical lymph node metastasis (P<0.05), but not by age, tumor location on the thyroid, size, single central lymph node metastasis, distant metastasis and operative approach (P>0.05). The significant factors associated with recurrent PTMC were subjected to stepwise multivariate Cox proportional hazards regression model analysis and the results indicated that BRAF V600E, sex, multifocality and lateral cervical lymph node metastasis were independent factors influencing recurrence in patients with PTMC, with a statistically significant difference (P<0.05). In conclusion, BRAF V600E, sex, multifocality and lateral cervical lymph node metastasis are independent risk factors for recurrent PTMC.

Diagnostic Accuracy of Contrast-Enhanced Ultrasonography in Papillary Thyroid Microcarcinoma Stratified by Size

We explored the diagnostic accuracy of ultrasonography (US) in papillary thyroid microcarcinoma (PTMC), studying nodular growths according to size via 3-D color Doppler US (3-DCDUS) and contrast-enhanced US (CEUS). A total of 109 patients undergoing CEUS and surgery of thyroid nodules at the First Hospital of China Medical University between January 2017 and December 2018 were selected for the study, including 77 with post-operative pathologically confirmed PTMC (test group) and 32 with nodular goiter (controls). All nodules were ≤1.0 cm in maximum diameter. After 3-DCDUS, each patient underwent Thyroid Imaging Reporting and Data System (TI-RADS) grading. In both groups, receiver operating characteristic curve analysis of anteroposterior (AP) nodule diameters was conducted, establishing a cutpoint for probable malignancy by CEUS. In the test group (n = 77), grading was as follows: TI-RADS 4a, 23; TI-RADS 4b, 40; TI-RADS 4c, 14. More patients had heterogeneous enhancement or hypo-enhancement (n = 55) than uniform hyper-enhancement or uniform iso-enhancement (n = 22) by contrast-enhanced ultrasonography (CEUS). Control group (n = 32) grading was as follows: TI-RADS 3, 1; TI-RADS 4, 21; TI-RADS 4b, 10. Fewer patients had heterogeneous enhancement or hypo-enhancement (n = 12) than uniform hyper-enhancement or uniform iso-enhancement (n = 20) by CEUS. The diagnostic accuracy of 3-DCDUS or CEUS differed significantly from that of 3-DCD-US + CEUS (p < 0.05), whereas 3-DCDUS and CEUS performed similarly (p > 0.05). At AP diameters of 0.66 cm, the Youden index for diagnosing malignancy by CEUS was maximal. When nodules below this threshold were excluded, both CEUS and 3-DCDUS + CEUS improved significantly in diagnostic accuracy (p < 0.05). CEUS is useful in determining the status (benign vs. malignant) of thyroid nodules, with significantly better accuracy at AP diameters ≥0.66 cm.

The anteroposterior diameter of nodules in the risk assessment of papillary thyroid microcarcinoma

This study investigates the application of ultrasound, especially the anteroposterior diameter of nodules in the malignancy and metastasis risk assessment of papillary thyroid microcarcinoma through a retrospective analysis of 500 cases of thyroid nodule ultrasonography.We selected 500 patients with thyroid nodules (maximum nodule diameter ≤2.0 cm) that had been diagnosed clinically and graded TI-RADS 4c by ultrasonography and surgically treated. Among these, there were 258 cases of pathologically diagnosed papillary thyroid microcarcinoma, 72 cases of nodular goiter or adenoma, 137 cases of papillary thyroid carcinoma, 28 cases of acinar cell carcinoma, and 5 cases of undifferentiated carcinoma. In all cases, color Doppler ultrasonography had been performed preoperatively to determine the size and number of nodules, surrounding lymph node metastasis, and TI-RADS grading. Cases of papillary thyroid microcarcinoma diagnosed by pathology were selected as the study group, and cases of nodular goiter or adenoma as the control group. Each group was further subdivided based on the anteroposterior, vertical, and transverse nodule diameters. Intergroup statistical analysis was also performed. Receiver operating characteristic (ROC) curve analysis was conducted on the study and control groups based on the anteroposterior nodule diameters, and the optimal critical value for malignancy risk was determined. Thyroid nodules in the study group were divided into groups based on the presence or absence of lymph node metastasis. Based on the anteroposterior nodule diameter, ROC curve analysis was performed, and the optimal critical value for metastasis risk was determined.There were 500 cases of malignant nodules diagnosed by ultrasound. Among these, there were 428 cases of malignant nodules diagnosed by pathology. The coincidence rate of the ultrasound diagnosis with pathological diagnosis was 85.60%. While, interestingly, There was a significant statistical difference between the study and control groups based on the anteroposterior nodule diameter. When the anteroposterior nodule diameter was 0.7 cm, sensitivity of malignant diagnosis was 76.70% and specificity of that was 66.70%, and the Youden index was the highest. The lymph node metastasis rate for papillary thyroid microcarcinoma was 13.95%. Within this group, the lymph node metastasis rate for nodules ≥0.9 cm (anteroposterior diameter) was 38.46%. When the anteroposterior nodule diameter was equal to 0.9 cm, sensitivity of diagnosis was 83.30%, and specificity of that was 77.80%, and the Youden index was the highest.The anteroposterior diameter of thyroid nodules is more suitable for assessing their malignancy with 0.7 cm, which can be used as the critical value. Nodules ≥ 0.7 cm require surgical treatment, and those <0.7 cm can be observed. An anteroposterior diameter of 0.9 cm can be used as the critical value for assessing the metastasis risk of malignant thyroid nodules. During surgery, the dissection of central cervical lymph nodes is required for nodules ≥0.9 cm.

A registry-based study of thyroid paraganglioma: histological and genetic characteristics

The precise diagnosis of thyroid neoplasias will guide surgical management. Primary thyroid paraganglioma has been rarely reported. Data on prevalence, immunohistochemistry (IHC), and molecular genetics in a systematic series of such patients are pending. We performed a multinational population-based study on thyroid paraganglioma and analyzed prevalence, IHC, and molecular genetics. Patients with thyroid paraganglioma were recruited from the European-American-Head-and-Neck-Paraganglioma-Registry. Demographic and clinical data were registered. Histopathology and IHC were re-investigated. All patients with thyroid paraganglioma underwent molecular genetic analyses of the SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, RET, TMEM127, and MAX genes. Analyses included Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) for detection of large rearrangements. Of 947 registrants, eight candidates were initially identified. After immunohistochemical analyses of these eight subjects, 5 (0.5%) were confirmed to have thyroid paraganglioma. IHC was positive for chromogranin, synaptophysin, and S-100 and negative for calcitonin in all five thyroid paragangliomas, whereas the three excluded candidate tumors stained positive for pan-cytokeratin, a marker excluding endocrine tumors. Germline variants, probably representing mutations, were found in four of the five confirmed thyroid paraganglioma cases, two each in SDHA and SDHB, whereas the excluded cases had no mutations in the tested genes. Thyroid paraganglioma is a finite entity, which must be differentiated from medullary thyroid carcinoma, because medical, surgical, and genetic management for each is different. Notably, approximately 80% of thyroid paragangliomas are associated with germline variants, with implications for additional tumors and a potential risk for the family. As opposed to sporadic tumors, surgical management and extent of resection are different for heritable tumors, each guided by the precise gene involved.