Detection of lymph node metastases of papillary thyroid cancer-comparison of the results of histopathology, immunohistochemistry and reverse transcription-polymerase chain reaction-a preliminary report

The clinical significance of the features of the morphological study and immunohistochemical determination of pancytokeratin in the lymph nodes of the central zone in papillary thyroid cancer

Introduction. papillary thyroid cancer is increasingly being detected at early stages when regional and distant metastases are absent per clinical examination. However, lymph nodes of the central zone can carry hidden metastases. frequency of such metastases is 22.3–46.7 %. maximally accurate identification of hidden metastases after lymph node dissection remains an important problem.

Aim. тo evaluate the effect of histological examination characteristics and immunohistochemical measurement of pancytokeratin level on frequency of detection of papillary cancer hidden metastases in regional lymph nodes of the central zone in patients with clinical stage N0 papillary cancer.

Materials and methods. The main group included 50 patients with stage ст1–2N0М0 primary papillary thyroid cancer. Dissected central lymph nodes of the patients prior to formalin fixation were extracted from the sample and inserted in individual paraffin blocks. Apart from standard histological examination, pancytokeratin level was measured immunohistochemically in the lymph nodes. The control group consisted of 200 patients for whom dissected central cell tissue was sectioned into blocks after formalin fixation. The number of lymph nodes in the dissected sample was measured by a pathomorphologist.

Results. In the main group, the number of lymph nodes in the sample varied between 6 and 37 with mean of 20.7 ± 6.8; in the control group the number was lower: 3–25, mean 9.8 ± 5.1 (р = 0.000). In the main group, hidden metastases were detected more frequently than in the control group: in 30 (60 %) and 68 (34 %) cases, respectively (р = 0.001). In 20 (40 %) patients, immunohistochemical examination showed new metastases. use of this method allowed to detect 1 to 7 additional metastases (mean 2.4 ± 1.5 lymph node lesions).

Conclusion. use of targeted dissection with extraction of lymph nodes led to significant increase in their numbers in the samples, and immunohistochemical examination allowed to detect a large number of hidden metastases in the central lymph nodes.

Diagnostic value of cytology, thyroglobulin, and combination of them in fine-needle aspiration of metastatic lymph nodes in patients with differentiated thyroid cancer: A systematic review and network meta-analysis

BACKGROUND

To investigate the diagnostic performance of cytology (fine-needle aspiration cytology [FNAC]), thyroglobulin (fine-needle aspiration thyroglobulin [FNA-Tg]), and combination of them in the washout of fine-needle aspiration for those patients who have suspicious metastatic lymph nodes of differentiated thyroid cancer.

METHODS

Databases, including PubMed, EMbase, Web of Science and Cochrane Library were searched up to June 2019. The quality assessment of diagnostic accuracy scale-2 was used to conduct quality assessments, and publication bias was evaluated using the Deeks funnel plot. STATA version 14.0 was used to perform the meta-analysis.

RESULTS

A total of 2257 patients with 2786 samples of suspicious metastatic lymph nodes of differentiated thyroid cancer were included in the meta-analysis. The results showed that the diagnostic value for detecting lymph node metastasis of differentiated thyroid cancer was as follows: combination of FNAC and FNA-Tg > FNA-Tg > FNAC. All differences of superiority among them are statistically significant. The sensitivity of the combination was 0.968 (95% confidence interval [CI]: 0.942-0.983), the specificity was 0.932 (95% CI: 0.856-0.969), the diagnostic score was 6.036 (95% CI: 4.892-7.181), the diagnostic odds ratio was 418.424 (95% CI: 133.167-1314.729), and the score of summary receiver operating characteristic was 0.99 (95% CI: 0.97-0.99).

CONCLUSIONS

The combination of FNAC and FNA-Tg is an excellent procedure in diagnosis of lymph nodes metastasis of patients with differentiated thyroid cancer, which should be highly recommended.

Cervical lymph node thyroglobulin measurement in washout of fine-needle aspirates for diagnosis of papillary thyroid cancer metastases

BACKGROUND

Patients with papillary thyroid cancer (PTC) and enlarged cervical lymph nodes (CLNs) are usually assessed by fine-needle aspiration biopsy cytology (FNAB-C). Thyroglobulin (Tg) is frequently detected in washout of fine-needle aspirates (FNA) of these lymph nodes. The aim of this study was to evaluate the accuracy of the measurement of FNAB-Tg in the washout of FNAB in combination with FNAB-C to detect CLN metastases in PTC.

METHODS

We retrospectively evaluated 163 surgically proven CLNs. Ultrasound-guided FNAB-C and FNAB-Tg measurements were performed and the ultrasound features were evaluated.

RESULTS

The sensitivity, specificity and accuracy of FNAB-C, FNAB-Tg and FNAB-C/FNAB-Tg in diagnosis of metastatic CLNs were 85.7, 87.8 and 71.6%, were 80.5, 87 and 82.8% and were 97.1, 96.3 and 95.7%, respectively. The diagnostic sensitivity, specificity and accuracy of FNAB-C/FNAB-Tg for metastatic CLNs was significantly higher than that of FNAB-C or FNAB-Tg alone (p < 0.01).

CONCLUSION

Combined US-guided FNAB-C and FNAB-Tg can improve the accuracy for diagnosis of metastatic CLNs in patients with PTC.

Cervical lymph node metastases from thyroid cancer: does thyroglobulin and calcitonin measurement in fine needle aspirates improve the diagnostic value of cytology?

Background

Measurement of thyroglobulin (Tg) protein in the washout of the needle used for fine needle aspiration biopsy cytology (FNAB-C) has been shown to increase the sensitivity of FNAB-C in identifying cervical lymph node (CLN) metastasis from well-differentiated thyroid cancer (TC). In this study, we evaluated whether routine measurement of Tg protein (FNAB-Tgp), Tg mRNA (FNAB-Tgm) and calcitonin (CT) mRNA (FNAB-CTm) in the FNAB washout of CLN increases the accuracy of FNAB-C in the diagnosis of suspicious metastatic CLN.

Methods

In this prospective study 35 CLN from 28 patients were examined. Histology showed metastatic papillary TC (PTC) in 26 CLN, metastatic medullary TC (MTC) in 3 CLN, metastatic anaplastic TC (ATC) in 3 CLN and 3 metastatic CLN from extra-thyroidal cancers.

Results

The overall accuracy of FNAB-C was 84.4%, reaching 95.7% when the analysis was restricted to PTC. Both FNAB-Tgp and FNAB-Tgm compared favorably with FNAB-C and shown diagnostic performances not statistically different from that of FNAB-C. However, FNAB-Tgp and FNAB-Tgm/FNAB-CTm were found useful in cases in which cytology results were inadequate or provided diagnosis inconsistent with patient's clinical parameters.

Conclusions

We demonstrated that FNAB-C, Tg/CT mRNA and Tg protein determination in the fine-needle washout showed similar accuracy in the diagnosis of metastatic CLN from TC. The results of this study suggest that samples for Tg protein and Tg/CT mRNA measurements from CLN suspicious for metastatic TC should be collected, but their measurements should be restricted to cases in which FNAB-C provides uninformative or inconsistent diagnosis with respect to patient's clinical parameters.