title: Thyroid fine needle aspiration biopsy: do nodule volume and cystic degeneration ratio affect specimen adequacy and cytological diagnosis time?
abstract: BACKGROUND
  A fine needle aspiration biopsy (FNAB) of thyroid nodules - the least invasive and most accurate method used to investigate malignant lesions - may yield non-diagnostic specimens even under ultrasonographic guidance.
  
  
  OBJECTIVE
  To evaluate the effects of thyroid nodule volume and extent of cystic degeneration on both the non-diagnostic specimen ratio as well as cytopathologist's definitive cytological diagnosis time.
  
  
  METHODS
  In this single center study, FNAB was performed on 505 patients with single thyroid nodules greater than 10 mm. Nodule volume was calculated prior to FNAB and cystic degeneration ratio was recorded. All biopsies were performed by a single radiologist who also prepared specimen slides. Specimen adequacy and final diagnosis were made in the pathology laboratory by a single-blinded cytopathologist based on the Bethesda system. Definitive cytological diagnosis time was recorded upon reaching a definitive diagnosis.
  
  
  RESULTS
  The specimen adequacy ratio was 85.3%. The mean nodule volume of adequate specimens was larger than those of non-diagnostic samples (6.00 mL vs. 3.05 mL; P = 0.001). There was no correlation between nodule volume and cytopathologist's definitive cytological diagnosis time (r = 0.042). Biopsy of predominantly solid nodules yielded better specimen adequacy ratios compared to predominantly cystic nodules (87.8% vs. 75.3%; P = 0.028). Definitive cytological diagnosis times were longer in predominantly cystic nodules compared to predominantly solid nodules (376 s vs. 294 s; P = 0.019).
  
  
  CONCLUSIONS
  Predominantly cystic nodules are likely to benefit from repeated nodular sampling until the specimen is declared adequate by an on-site cytopathologist. If a cytopathologist is not available, obtaining more specimens per nodule may achieve desired adequacy ratios.
authors.affiliation: Department of Radiology, Van Bolge Research and Education Hospital, Van, Turkey.
authors.forename: Ismet
authors.initials: I
authors.lastname: Cengic
authors.affiliation: Department of Radiology, Ercis State Hospital, Ercis, Van, Turkey deryatureli@yahoo.com.
authors.forename: Derya
authors.initials: D
authors.lastname: Tureli
authors.affiliation: Department of Pathology, Van Bolge Research and Education Hospital, Van, Turkey.
authors.forename: Ferhat
authors.initials: F
authors.lastname: Ozden
authors.affiliation: Department of Radiology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Onur
authors.initials: O
authors.lastname: Bugdayci
authors.affiliation: Department of Radiology, Ercis State Hospital, Ercis, Van, Turkey.
authors.forename: Hilal
authors.initials: H
authors.lastname: Aydin
authors.affiliation: Department of Radiology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Erkin
authors.initials: E
authors.lastname: Aribal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000473:pathology*; D016606:Thyroid Nodule / Q000473:pathology*; D018084:Ultrasonography, Interventional
keywords: Thyroid nodule; cystic degeneration ratio; fine needle aspiration biopsy; nodule size; specimen adequacy