Cervical Lymph Node Fine-Needle Aspiration and Needle-Wash Thyroglobulin Reflex Test for Papillary Thyroid Carcinoma

The Unique Importance of Differentiation and Function in Endocrine Neoplasia

The assessment of cell differentiation in endocrine neoplasms involves not only the identification of a cell's structure and expression of specific transcription factors which regulate that cell, but also the identification of hormones and/or enzymes involved in hormone synthesis. The importance of this functional characterization is emphasized by the fact that the hormones serve as biomarkers for clinical surveillance to identify persistence, recurrence, or progression of disease. Sometimes, unusual patterns of hormone expression lead to unexpected clinical signs and symptoms. Loss of differentiated hormone production can be a sign of dedifferentiation as a tumor becomes more aggressive. In addition to prognostic information, cell differentiation can be predictive, since differentiated endocrine cells express targets for therapy, such as the sodium iodide symporter in thyroid cancers and somatostatin receptors in neuroendocrine tumors. The salient features of differentiation in the three main types of endocrine cells can be used to determine prognosis and to tailor management of patients with endocrine neoplasms.

Laterocervical lymph node metastases from suspected thyroidal primary site that turned out to be metastases of lung cancer: A case report

Incidental sonographic discovery of thyroid nodules is an increasingly common event in clinical practice. Less frequently, patients with cytological benign thyroid nodules have suspicious cervical lymph nodes detected by ultrasound examination or by cytological exam. Here, we discuss an intriguing case of cervical lymph node metastasis with a probable thyroid origin in a 65-year-old asymptomatic male smoker. He underwent thyroidectomy and unilateral cervical lymphadenectomy. Despite a negative chest X-ray, the postoperative histological examination revealed that the lymph node metastasis was actually from a lung carcinoma. Metastatic lesions in cervical lymph nodes from non-thyroidal origins must be excluded when evaluating lesions in the region, especially when thyroid nodules subjected to fine needle aspiration biopsy yield negative results, or lymph node cytological evaluations are inconsistent with thyroid cytological findings and sonographic features. Thyroid and lung adenocarcinomas share some epithelial and mesenchymal markers. Thyroglobulin helps differentiate primary thyroid tumors from lung ones, but in cases of poor differentiation, distinguishing metastatic lesions in the thyroid gland can be challenging. Lung cancer (LC) is the leading cause of cancer mortality worldwide, and survival rates have only marginally improved over the last several decades. The ongoing clinical challenge is detecting LC at earlier stages of the disease.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Detection of thyroglobulin in fine-needle aspiration for diagnosis of metastatic lateral cervical lymph nodes in papillary thyroid carcinoma: A retrospective study

Objective

We analysed the diagnostic performance of thyroglobulin in fine-needle aspiration (FNA-Tg) in the suspicious lateral cervical lymph nodes (CLNs) in patients with papillary thyroid cancer (PTC), proposed the best cutoff value and discussed the factors that may affect the diagnostic value of FNA-Tg.

Methods

In the present study, a retrospective analysis of 403 patients with PTC with 448 suspected lateral CLNs metastasis from October 2019 to May 2021 was performed. The cutoff value according to the receiver operating characteristic (ROC) curve was determined, and the Wilcoxon rank-sum test was used to evaluate the correlation between FNA-Tg and factors.

Results

According to the ROC curve, the cutoff value of FNA-Tg was 3.69 ng/ml (sensitivity, 92.48%; specificity, 75.00%). Patients who underwent total thyroidectomy were excluded. Compared with US and FNAC, the diagnostic performance of FNA-Tg was the greatest, especially for small CLNs (diameter ≤ 1 cm), cystic CLNs, and patients with Hashimoto’s thyroiditis (HT). Moreover, FNA-Tg levels were correlated with the presence of HT (p = 0.003), the anti-thyroglobulin antibody (Tg-Ab) (p < 0.001), the ratio of metastatic lateral CLNs (p = 0.004) and Tg assay kits (p < 0.001).

Conclusions

FNA-Tg measurement is sensitive enough for diagnosing lateral CLN metastases from PTC, but its diagnostic value is compromised by a number of factors.

Impact of Thyroid Tissue Status on the Cut-Off Value of Lymph Node Fine-Needle Aspiration Thyroglobulin Measurements in Papillary Thyroid Cancer

Objective: To study the optimal cut-off value of thyroglobulin measurement in a fine-needle aspiration (FNA-Tg) in diagnosing malignant lymph nodes and benign lymph nodes (LNs) according to the thyroid tissue status.

Methods: A total of 517 LNs were aspirated: 401 preoperative LNs, 42 LNs after subtotal thyroidectomy and 74 suspected LNs after total thyroidectomy. The cut-off value of FNA-Tg was obtained from receiver operating characteristic (ROC) analysis. The cut-off value with the best diagnostic performance was then obtained by comparing different cut-off values from other studies.

Results: LN FNA-Tg levels differed between preoperative and total thyroid disease (p < 0.001) and subtotal thyroidectomy and total thyroidectomy (p = 0.03), but not between preoperative and subtotal thyroidectomy (p = 1.00). Accordingly, those 443 LNs with preoperative and subtotal thyroidectomy were compared to those 74 without thyroid tissue. The optimal cut-off value in thyroid tissue group was 19.4 ng/ml and the area under the ROC curve (AUC) was 0.95 (95% CI 0.92–0.97). The optimal cut-off value in thyroid tissue absence group was 1.2 ng/ml and the AUC was 0.93 (0.85–0.98). After the analysis and comparison of multiple cut-off values, the optimal diagnostic performance was still found to be 19.4 ng/ml and 1.2 ng/ml.

Conclusion: The influential factors of FNA-Tg are still controversial, and the optimal cut-off value of FNA-Tg can be determined based on the presence or absence of thyroid tissue. FNA-Tg can be used as an important auxiliary method for diagnosing cervical metastatic LNs of thyroid cancer.

Predictive Value of FNA-Tg and TgAb in Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma

Objectives: To analyze whether thyroglobulin (Tg) and anti-Tg antibody (TgAb) detection in fine-needle aspiration (FNA) of cervical lymph node (LN; LN-FNA-Tg and LN-FNA-TgAb) can predict LN metastasis and obtain the best cutoff value. Methods: The patients admitted to our hospital from January 2020 to March 2021 were prospectively enrolled. The LNs were sampled by FNA. All patients underwent thyroid surgery and neck dissection. LN-FNA-Tg, LN-FNA-TgAb, and blood Tg and TgAb were measured. The receiver operating characteristic curve analysis was used to determine the best cutoff points for positive LN. Results: There were 29 participants in the LN metastasis group and 42 in the nonmetastasis group. Compared with the nonmetastasis group, the participants in the metastasis group had higher LN-FNA-Tg (median: 1897 vs 7.74 ng/mL, P < .001), higher LN-FNA-TgAb (median: 15.65 vs 8.21 IU/mL, P < .001), and higher serum Tg (median: 25.4 vs 18.81 ng/mL); there were no differences in serum TgAb (median: 26.6 vs 28.6 IU/mL, P = .477). The best accuracy (87.5%) was observed with LN-FNA-Tg of >227.1 ng/mL, resulting in an area under the curve of 0.927, 84.5% sensitivity, and 89.5% specificity. LN-FNA-TgAb >10.85 IS/mL had an accuracy of 79.6%, sensitivity 64.8%, and specificity 89.5%. Serum Tg and TgAb had the lowest accuracy, with 64.2% and 57.4%, respectively, sensitivity of 53.5% and 67.6%, and specificity of 71.4% and 50.5%. Similar results were observed in first-operation participants and postoperative participants. Conclusions: LN-FNA-Tg has high accuracy, sensitivity, and specificity for detecting cervical LN in patients with papillary thyroid cancer.

The diagnostic value of thyroglobulin in fine-needle aspiration of metastatic lymph nodes in patients with papillary thyroid cancer and its influential factors

Thyroglobulin (Tg) measurement in fine-needle aspiration (FNA-Tg) has proved to be an excellent tool to identify metastatic cervical lymph nodes (CLN) before or after surgery for papillary thyroid cancer (PTC). The diagnostic value of FNA-Tg for metastatic CLN in PTC patients is higher than that of ultrasound (US) and fine-needle aspiration cytology (FNAC), especially for small or cystic LN. The combination of FNAC and FNA-Tg can provide nearly 100% diagnostic sensitivity and specificity for CLN metastasis. However, the cutoff values of FNA-Tg for metastatic CLN have not been standardized, and the reported cutoff values of FNA-Tg range from 0.2 ng/ml to 77 ng/ml because of the differences in study samples, Tg measurement methods, Tg assays kits, etc. Serum anti-thyroglobulin antibody level, serum thyroglobulin level, the presence or absence of thyroid glands, and the characteristics of CLN may be factors affecting the accuracy of FNA-Tg. This review summarizes the recent research on the application of FNA-Tg in the diagnosis of metastatic LN in PTC and provides a reliable basis for the clinical diagnosis of cervical lymph node metastasis.

Excellent diagnostic performance of FNA-Tg in detecting lymph nodes metastases from papillary thyroid cancer

Background: Thyroglobulin washout of fine needle aspiration (FNA-Tg) has proved to be useful in detecting lymph node metastases from papillary thyroid cancer; however, the influences of thyroid gland, Hashimoto thyroiditis, serum thyroglobulin (Tg) and anti-TG antibody on the diagnostic performance of FNA-Tg are controversial. Patients & methods: We retrospectively collected the FNA-Tg results of 176 preoperative or postoperative patients (356 lymph nodes) who finally were diagnosed with papillary thyroid cancer. The diagnostic abilities of FNA-Tg were evaluated and compared under different circumstances. Results: The diagnostic performance of FNA-Tg was uninfluenced irrespective of the status of thyroid gland or serum anti-TG antibody. However, high serum Tg was positively correlated with FNA-Tg (Exp(B) = 1.57; 95% CI: 1.209-2.309; p = 0.001). Conclusion: FNA-Tg was an excellent diagnostic tool, but it should be interpreted with caution only if serum Tg is higher than 10 ng/ml.

Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review

Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.