title: US diagnosis of cervical recurrence in patients operated on thyroid cancer: sonographic features and clinical significance.
abstract: OBJECTIVE
  To describe the sonographic features of cervical recurrence in patient with thyroid cancer and review clinical significance.
  
  
  METHODS
  Twenty-two consecutive patients with 24 surgically confirmed recurrences undergoing preoperative ultrasonography (US) and US-guided fine needle aspiration biopsy (FNAB) were enrolled. Retrospective analysis was conducted on the sonographic features of recurrence including size, location, shape, echogenicity, multiplicity, laterality relative to initial primary tumor and presence of characteristic findings; cystic change and microcalcification. In addition, review was made on their clinical data including the time interval between the thyroidectomy and the recurrence, serum thyroglobulin (Tg), anti-thyroglobulin antibody (Tg Ab) and 131 iodine whole body scan (IWBS).
  
  
  RESULTS
  Fifteen of 24 recurrences occurred in internal jugular lymphatic chain and 9 in the postoperative paratracheal region with mostly ipsilaterally to the initial tumor (19/24). Their mean size was 1.0 cm (range: 0.5-2.5 cm) with ovoid (n=18) or lobulated (n=6) shape. They appeared hyperechoic in nine (37.5%), hypoechoic in nine (37.5%), and mixed echoic due to cystic change in six (25.0%). Microcalcification was observed in eight (33.3%) and multiplicity in seven (29.2%). US-guided FNAB established the preoperative diagnosis of recurrence in all. The mean interval between the thyroidectomy and recurrence was 59 months (range: 15-162 months). Suspicion of recurrence was possible in 8 with Tg of 2 ng/ml or greater (8/24) during thyroxine (T4) therapy and 6 (6/8) after T4 withdrawal. All of the 8 recurrences were negative on 131 IWBS. In two patients with Tg less than 2 ng/ml after T4 withdrawal, elevated Tg Ab was observed.
  
  
  CONCLUSIONS
  US and US-guided FNAB are valuable postoperative follow up modalities of thyroid cancer due to their convenience, early detection and precise localization. Therefore, it's essential to get familiar with sonographic findings of cervical recurrence.
authors.affiliation: Department of Radiology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Hen
authors.initials: YH
authors.lastname: Lee
authors.forename: Nam Joon
authors.initials: NJ
authors.lastname: Lee
authors.forename: Jung Hyuk
authors.initials: JH
authors.lastname: Kim
authors.forename: Jae Jun
authors.initials: JJ
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood; D044963:Biopsy, Fine-Needle; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D013954:Thyroglobulin / Q000097:blood; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000473:pathology; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy; D013974:Thyroxine / Q000627:therapeutic use; D014463:Ultrasonography
chemical_list: D001323:Autoantibodies; D014408:Biomarkers, Tumor; C006606:anti-thyroglobulin; D013954:Thyroglobulin; D013974:Thyroxine