title: Thyroglobulin in lymph node fine-needle aspiration washout: a systematic review and meta-analysis of diagnostic accuracy.
abstract: BACKGROUND
  The thyroglobulin measurement in the needle washout after fine-needle aspiration (FNA) has been reported to increase the sensitivity of FNA in identifying lymph node (LN) metastases from differentiated thyroid cancer (DTC).
  
  
  OBJECTIVE
  The aim of the study was to estimate the diagnostic accuracy of this technique.
  
  
  METHODS
  To identify eligible studies, we searched electronic databases for original articles in English from 1975 through 2013.
  
  
  METHODS
  Studies that enrolled participants with suspicious neck LNs during thyroid nodule workup or thyroid cancer follow-up were included.
  
  
  METHODS
  Working independently, authors used a standard form to extract data. For quality assessment, QUADAS2 guidelines were applied.
  
  
  RESULTS
  Including all the selected studies (24 studies, 2865 LNs) in the pooled analysis, overall sensitivity was 95.0% (95% confidence interval [CI], 93.7-96.0%), specificity was 94.5% (95% CI, 93.2-95.7%), and diagnostic odds ratio (DOR) was 338.91 (95% CI, 164.82-696.88) with significant heterogeneity (inconsistency [I(2)] = 65.7%; heterogeneity, P < .001). Stratifying different populations and including only patients with thyroid gland (410 LNs), pooled sensitivity was 86.2% (95% CI, 80.9-90.5%), specificity was 90.2% (85.1-94.0%), and DOR was 56.621 (22.535-142.26; I(2) = 37.3%; heterogeneity, P = .121). Including only patients after thyroidectomy (1007 LNs), pooled sensitivity was 96.9% (95% CI, 94.9-98.2%), specificity was 94.1% (91.7-96.0%), and DOR was 407.65 (198.67-836.46; I(2) = 0.0%; heterogeneity, P = .673).
  
  
  CONCLUSIONS
  Thyroglobulin measurement in washout from LN FNA has high accuracy in early detection of nodal metastases from DTC. The technique is simple, but a better standardization of criteria for patient selection, analytical methods, and cutoff levels is required.
authors.affiliation: Department of Experimental Medicine, Unit of Endocrinology, "Sapienza" Università di Roma, 00161 Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Grani
authors.forename: Angela
authors.initials: A
authors.lastname: Fumarola
mesh_terms: D044963:Biopsy, Fine-Needle; D018265:Carcinoma, Papillary, Follicular / Q000175:diagnosis* / Q000473:pathology*; D003430:Cross-Sectional Studies / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies / Q000706:statistics & numerical data; D008198:Lymph Nodes / Q000737:chemistry* / Q000473:pathology*; D008207:Lymphatic Metastasis; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000032:analysis*; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology*
chemical_list: D013954:Thyroglobulin