Diagnostic values of thyroglobulin in lymph node fine-needle aspiration washout: a systematic review and meta-analysis diagnostic values of FNA-Tg

Abstract

Thyroglobulin measurement in the needle washout after fine-needle aspiration (FNA-Tg) served as an important measurement for suspicious recurrent or metastatic lesions. We conducted a pooled analysis to evaluate the diagnostic accuracy of FNA-Tg and searched electronic databases for original articles in English from 1993 through 2017. Finally, a total of 22 studies containing 2,670 lymph nodes (LNs) that enrolled participants with suspicious neck LNs during thyroid nodule workup or papillary thyroid cancer (PTC) follow-up were included. In our analysis, the overall pooled sensitivity for FNA-Tg was 0.91 (95%CI: 0.87-0.93), specificity was 0.94 (95% CI: 0.91-0.96). Meta regression revealed that the cutoff value and status of serum Tg were sources of heterogeneity for sensitivity, and the cutoff value was source of heterogeneity for specificity. Additionally, the cutoff value and status of serum Tg were sources of heterogeneity in the joint model. Subgroup analysis about cut-off value showed that the choice of 1 ng/mL had highest sensitivity, 40 ng/mL had highest specificity. At last, we arrived at the conclusion that FNA-Tg measurement had high specificity and sensitivity in the early detection of LNs metastases from PTC by our meta-analysis. The technique was simple and could be recommended to apply in any FNA facility, especially when LN were small-sized. Significantly, a better standardization of criteria for FNA-Tg detection and cutoff value was required to provide useful data and to improve management of PTC patients in the future.

Fine Needle Biopsy Versus Core Needle Biopsy Combined With/Without Thyroglobulin or BRAF 600E Mutation Assessment for Detecting Cervical Nodal Metastasis of Papillary Thyroid Carcinoma

“…Cervical LNM was suggested if there were the following features, for ultrasound: absence of an echogenic hilum, round shape, microcalcification, peripheral blood flow on color Doppler images, or cystic changes (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18); for CT: area with clear evidence of nonfat, low-density, or liquid components; largest diameter >15 mm at level II and >10 mm at other levels; and ratio of the longest to smallest diameter ≤2.…”

“…Ultrasound-guided fine needle aspiration biopsy cytology (FNAB-C) and core needle biopsy tissue (CNB-T) play an important role in evaluating cervical lymph node status in thyroid cancer and head and neck squamous cell carcinoma (SCC), respectively (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). However, the value of FNAB-C is greatly limited if the number of specimens is small or the specimens are obtained from cystic lymph nodes.…”

“…Since it was first described by Pacini et al (11), the measurement of thyroglobulin (Tg) in the washout of the needle (FNAB-Tg) has attracted increasing attention because of its higher reliability than FNAB-C (12)(13)(14)(15). However, there is still great controversy regarding the best cutoff value of FNAB-Tg and whether serum thyroid stimulating hormone (TSH), thyroglobulin antibody (TgAb), serum Tg, and thyroid tissue interfere with the accuracy of FNAB-Tg (16,17). Some researchers have reported that the clinical performance of FNAB-Tg was not affected by TgAb and TSH (10,12), but others have asserted that the diagnostic value of FNAB-Tg could be greatly influenced by the presence of thyroid tissue, serum Tg, and TgAb (7,14,15,18).…”

Thyroglobulin measurements in washouts of fine-needle aspiration biopsy in the monitoring of patients with differentiated thyroid carcinoma

“…The last meta-analysis based on the largest published studies found that a FNAB-Tg cut-off value of 1 ng/mL had highest sensitivity and 40 ng/mL had highest specificity [9]. An FNAB-Tg cut-off value has not been unanimously established.…”

“…This assay was first proposed by Pacini et al, and despite being recommended by many guidelines the technique is not standardized [8]. There are considerable differences between various diagnostic centres regarding the methodology of measurement of Tg levels as well as cut-off values for FNAB-Tg in positive cases (varying from 0.2 ng/mL to 100 ng/mL in different studies) [9].…”