title: Repeat Ultrasound-Guided Fine-Needle Aspiration for Thyroid Nodules 10 mm or Larger Can Be Performed 10.7 Months After Initial Nondiagnostic Results.
abstract: OBJECTIVE
  The purpose of this study is to investigate when repeat ultrasound (US)-guided fine-needle aspiration (FNA) for thyroid nodules 10 mm or larger with initial nondiagnostic results due to inadequate or unsatisfactory specimen could be performed.
  
  
  METHODS
  A total of 228 nodules 10 mm or larger with initial nondiagnostic results in 223 patients were classified into three groups according to the first follow-up US or US-guided FNA intervals after the initial US-guided FNA: within 3 months (group 1), 3-9 months (group 2), and more than 9 months (group 3). Nodules were classified according to size change. The malignancy detection rate and clinicopathologic characteristics were compared among the three groups.
  
  
  RESULTS
  Seven nodules (3.1%) were malignant, and their cancer stages were the same as that determined at the initial US-guided FNA. Malignancy detection rates, as well as tumor size, extrathyroidal extension, and lymph node metastasis at pathologic analysis, were not significantly different among the three groups. Thirteen of 228 nodules (5.7%) showed increased size at a mean (± SD) of 34.5 ± 25.1 months (range, 10.7-84.7 months) after initial US-guided FNA, and one of the 13 nodules (7.7%) was malignant, a minimally invasive follicular carcinoma without lymph node metastasis found at 63.2 months. Of 177 nodules without change, six papillary thyroid carcinomas (3.4%) were found at a mean of 10.4 months. None of the 38 nodules with decreased size during a mean follow-up interval of 26.1 ± 19.8 months (range, 2.8-79.5 months) was malignant.
  
  
  CONCLUSIONS
  Repeat US-guided FNA for initial nondiagnostic thyroid nodules after 10.7 months can reduce unnecessary repeat US-guided FNAs without progression of malignancy.
authors.affiliation: 1 All authors: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Moon
authors.affiliation: 1 All authors: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.affiliation: 1 All authors: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
authors.affiliation: 1 All authors: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Yonsei-ro 50, Seodaemun-gu, Seoul 120-752, Republic of Korea.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Yoon
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy; D008297:Male; D008875:Middle Aged; D019233:Retreatment; D012189:Retrospective Studies; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000473:pathology*; D013997:Time Factors; D018084:Ultrasonography, Interventional
keywords: fine-needle aspiration; nondiagnostic cytology; thyroid nodules; ultrasound