title: Potential causes for obtaining non-diagnostic results from fine needle aspiration biopsy of thyroid nodules.
abstract: OBJECTIVE
  The aim of this prospective study was to evaluate factors that could affect the diagnostic result success ratio of fine needle aspiration biopsy of thyroid nodules.
  
  
  METHODS
  664 patients and 696 nodules were included in this study. Demographic features of age and gender and nodule features of macrocalcification (MC) and internal content (cystic or solid predominance) were evaluated. All biopsies were performed from 1 cm or larger nodules. Three different size needles were used for comparison (22, 23 and 25 G). The patients in each group had a similar number of nodules with MC, and cystic predominance to obtain comparable results. All procedures were performed by the same radiologist, who had 4 years of experience. Histologically adequate material criteria were identified. All pathological specimens were evaluated as diagnostic or non-diagnostic by the same pathology technician. Chi-square, student's t test and univariate analysis were used for statistical analysis.
  
  
  RESULTS
  There were no statistically significant differences in demographic features and nodule properties from diagnostic results of fine needle aspiration biopsy of thyroid nodules. On the other hand, 23 G needles offered a better potential for obtaining adequate samples with a statistically significant difference.
  
  
  CONCLUSIONS
  Obtaining adequate material in fine needle aspiration biopsy from thyroid nodules is a challenging issue and the results are controversial. Since we obtained the best ratio with 23 G needles, we recommend interventional radiologists to use 23 G needles as far as possible and not to consider needles thicker needles than 22 G or thinner than 25 G. Nodule features and demographic features did not have an effect on obtaining adequate cytological material.
authors.affiliation: Okmeydani Education and Research Hospital, Radiology Clinic, Kaptanpasa Mah. Darülaceze Cad. No:27, Okmeydanı-ŞişliIstanbul, 34384, Istanbul, Turkey. denizozel34@hotmail.com.
authors.forename: Deniz
authors.initials: D
authors.lastname: Özel
authors.affiliation: Sisli Hamidiye Etfal Education and Research Hospital, Radiology Clinic, Istanbul, Turkey.
authors.forename: Betül Duran
authors.initials: BD
authors.lastname: Özel
authors.affiliation: Okmeydani Education and Research Hospital, Radiology Clinic, Kaptanpasa Mah. Darülaceze Cad. No:27, Okmeydanı-ŞişliIstanbul, 34384, Istanbul, Turkey.
authors.forename: Fuat
authors.initials: F
authors.lastname: Özkan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016606:Thyroid Nodule / Q000473:pathology*
keywords: Fine needle aspiration biopsy; Inadequate material; Thyroid nodules