title: Detection rate of FNA cytology in medullary thyroid carcinoma: a meta-analysis.
abstract: BACKGROUND
  The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine-needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta-analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates.
  
  
  METHODS
  A comprehensive computer literature search of the PubMed/MEDLINE, Embase and Scopus databases was conducted by searching for the terms 'medullary thyroid' AND 'cytology', 'FNA', 'FNAB', 'FNAC', 'fine needle' or 'fine-needle'. The search was updated until 21 March 2014, and no language restrictions were used.
  
  
  RESULTS
  Fifteen relevant studies and 641 MTC lesions that had undergone FNAC were included. The detection rate (DR) of FNAC in patients with MTC (diagnosed as 'MTC' or 'suspicious for MTC') on a per lesion-based analysis ranged from 12·5% to 88·2%, with a pooled estimate of 56·4% (95% CI: 52·6-60·1%). The included studies were statistically heterogeneous in their estimates of DR (I-square >50%). Egger's regression intercept for DR pooling was 0·03 (95% CI: -3·1 to 3·2, P = 0·9). The study that reported the largest MTC series had a DR of 45%. Data on immunohistochemistry for calcitonin in diagnosing MTC were inconsistent for the meta-analysis.
  
  
  CONCLUSIONS
  The presented meta-analysis demonstrates that FNAC is able to detect approximately one-half of MTC lesions. These findings suggest that other techniques may be needed in combination with FNAC to diagnose MTC and avoid false negative results.
authors.affiliation: Section of Endocrinology and Diabetology, Ospedale Israelitico, Rome, Italy; Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Trimboli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Treglia
authors.forename: Leo
authors.initials: L
authors.lastname: Guidobaldi
authors.forename: Francesco
authors.initials: F
authors.lastname: Romanelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nigri
authors.forename: Stefano
authors.initials: S
authors.lastname: Valabrega
authors.forename: Ramin
authors.initials: R
authors.lastname: Sadeghi
authors.forename: Anna
authors.initials: A
authors.lastname: Crescenzi
authors.forename: William C
authors.initials: WC
authors.lastname: Faquin
authors.forename: Massimo
authors.initials: M
authors.lastname: Bongiovanni
authors.forename: Luca
authors.initials: L
authors.lastname: Giovanella
mesh_terms: D044963:Biopsy, Fine-Needle; D018278:Carcinoma, Neuroendocrine; D005188:False Negative Reactions; D006801:Humans; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000473:pathology*; D016606:Thyroid Nodule / Q000453:epidemiology / Q000473:pathology*