title: Focal Lymphocytic Thyroiditis Nodules Share the Features of Papillary Thyroid Cancer on Ultrasound.
abstract: OBJECTIVE
  It is often difficult to discriminate focal lymphocytic thyroiditis (FLT) or adenomatous hyperplasia (AH) from thyroid cancer if they both have suspicious ultrasound (US) findings. We aimed to make a predictive model of FLT from papillary thyroid cancer (PTC) in suspicious nodules with benign cytologic results.
  
  
  METHODS
  We evaluated 214 patients who had undergone fine-needle aspiration biopsy (FNAB) and had shown thyroid nodules with suspicious US features. PTC was confirmed by surgical pathology. FLT and AH were confirmed through more than two separate FNABs. Clinical and biochemical findings, as well as US features, were evaluated.
  
  
  RESULTS
  Of 214 patients, 100 patients were diagnosed with PTC, 55 patients with FLT, and 59 patients with AH. The proportion of elevated thyrotropin (TSH) levels (p=0.014) and thyroglobulin antibody (Tg-Ab) or thyroid peroxidase antibody (TPO-Ab) positivity (p<0.001) in the FLT group was significantly higher than that in the PTC group. Regarding US features, absence of calcification (p=0.006) and "diffuse thyroid disease" (DTD) pattern on US (p<0.001) were frequently seen in the FLT group. On multivariate analysis, Tg-Ab positivity, presence of a DTD pattern on US, and absence of calcification in nodules were associated with FLT with the best specificity of 99% and positive predictive value of 96%. In contrast, a taller than wide shape of nodules was the only variable significant for differentiating AH from PTC.
  
  
  CONCLUSIONS
  Suspicious thyroid nodules with cytologic benign results could be followed up with US rather than repeat FNAB, if patients exhibit Tg-Ab positivity, no calcifications in nodules, and a DTD pattern on US.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sena
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong Yeob
authors.initials: DY
authors.lastname: Shin
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
authors.affiliation: Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Byun
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Gyuri
authors.initials: G
authors.lastname: Kim
authors.affiliation: Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: Soo Jung
authors.initials: SJ
authors.lastname: Im
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea. ejlee423@yuhs.ac.
authors.forename: Eun Jig
authors.initials: EJ
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies; D044963:Biopsy, Fine-Needle / Q000379:methods*; D002114:Calcinosis; D002277:Carcinoma / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D050031:Hashimoto Disease; D006801:Humans; D006965:Hyperplasia / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood; D000077273:Thyroid Cancer, Papillary; D013959:Thyroid Diseases; D013964:Thyroid Neoplasms / Q000473:pathology*; D016606:Thyroid Nodule / Q000473:pathology*; D013967:Thyroiditis, Autoimmune / Q000473:pathology*; D013972:Thyrotropin / Q000097:blood
chemical_list: D001323:Autoantibodies; C006606:anti-thyroglobulin; C056626:thyroid microsomal antibodies; D013972:Thyrotropin; D013954:Thyroglobulin
keywords: Differential diagnosis; focal lymphocytic thyroiditis; papillary thyroid cancer