title: Repeat fine-needle aspiration can be performed at 6 months or more after initial atypia of undetermined significance or follicular lesion of undetermined significance results for thyroid nodules 10 mm or larger.
abstract: OBJECTIVE
  To investigate whether repeat ultrasound-guided fine-needle aspiration (US-FNA) in initial atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) results could be performed 6 months after or more.
  
  
  METHODS
  A total of 221 AUS/FLUS ≥10 mm with any follow-up were grouped according to the first follow-up interval at less than 6 months (group 1, n = 87) and 6 months or more (group 2, n = 134). Clinical features, final assessment of ultrasound (US) or the Thyroid Imaging Reporting and Data System (TIRADS), tumour size, extrathyroidal extension and lymph node metastasis in malignancies were compared.
  
  
  RESULTS
  Thirty-four (15.4 %) were malignant. Age, gender, size, final assessment, TIRADS and malignancy rate were not significantly different between the two groups (p = 0.660, 0.691, 0.502, 0.237, 0.819 and 0.420). Tumour size, extrathyroidal extension and lymph node metastasis were not significantly different between the two malignancy groups (p = 0.770, 0.611 and 0.068). Two of 10 nodules with increased size were malignancies found at 7.1 and 25.0 months. None of 33 nodules (14.9 %) with decreased size at a median 10 months were malignant.
  
  
  CONCLUSIONS
  Repeat US-FNA performed on nodules ≥10 mm at 6 months or more after initial AUS/FLUS results can reduce unnecessary repeat US-FNAs without progression of malignancy.
  
  
  CONCLUSIONS
  • Follow-up intervals of AUS/FLUS did not affect the malignancy rate • Tumour stage was not different according to the follow-up intervals • None of the nodules with decreased size were malignant • Repeat US-FNA can be performed at ≥6 months after initial AUS/FLUS.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea, 120-752.
authors.forename: Jieun
authors.initials: J
authors.lastname: Koh
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea, 120-752.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea, 120-752.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea, 120-752.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea, 120-752. artemis4u@yuhs.ac.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Moon
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology*; D000328:Adult; D000359:Aftercare / Q000379:methods*; D018450:Disease Progression; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D000072637:Thyroid Epithelial Cells / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000473:pathology*; D016606:Thyroid Nodule / Q000473:pathology*; D047368:Tumor Burden
keywords: Cytology; Diagnosis; Fine-needle aspiration; Thyroid nodule; Ultrasound