title: Significance of what is not sampled: Characteristics of thyroid nonmicrocarcinomas (>1.0 cm) that were not targeted.
abstract: BACKGROUND
  Although most unsuspected thyroid carcinomas qualify as microcarcinomas (≤1 cm), larger, nontargeted carcinomas may be found also. This study evaluated the significance of these nonmicrocarcinomas (>1 cm) in the setting of a large-volume thyroid practice.
  
  
  METHODS
  Thyroid resection specimens from May 2007 to December 2012 were reviewed. For these cases, the pathologic characteristics of nontargeted carcinomas larger than 1.0 cm were evaluated. Those interpreted as intrathyroidal metastases were not included in this study. Specifically, the histologic classification, size, and molecular features were documented.
  
  
  RESULTS
  From a total of 4815 thyroid resections and 9279 thyroid fine-needle aspiration procedures that were performed during the study period, 27 nontargeted nonmicrocarcinomas were identified (0.6% of resection cases) in 26 patients. The histologic classifications were as follows: follicular variant of papillary carcinoma (n = 19), classic papillary carcinoma (n = 3), papillary carcinoma with oncocytic features (n = 1), tall-cell variant of papillary carcinoma (n = 2), and follicular carcinoma (n = 2). The size parameters were as follows: mean, 1.9 cm; median, 1.4 cm; and range, 1.1 to 7.0 cm. RAS and BRAF mutations were identified in 8 and 7 cases, respectively (71% of the cases tested with a 7-gene panel), whereas 6 cases showed no mutation. Molecular information was not available for 6 cases.
  
  
  CONCLUSIONS
  In the authors' experience, nontargeted thyroid nonmicrocarcinomas (>1 cm) are rare (0.6%), and the majority are low-grade carcinomas. The likelihood of finding one of the common mutations (71%) is comparable to the likelihood for thyroid carcinomas in general (∼70%).
authors.affiliation: Department of Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Schoedel
authors.affiliation: Department of Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Jenna
authors.initials: J
authors.lastname: Wolfe
authors.affiliation: Division of Endocrinology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Hodak
authors.affiliation: Division of Endocrinology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Shane O
authors.initials: SO
authors.lastname: Lebeau
authors.affiliation: Division of Endocrine Surgery, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Linwah
authors.initials: L
authors.lastname: Yip
authors.affiliation: Division of Endocrine Surgery, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Sally E
authors.initials: SE
authors.lastname: Carty
authors.affiliation: Department of Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Marina N
authors.initials: MN
authors.lastname: Nikiforova
authors.affiliation: Department of Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Nikiforov
authors.affiliation: Department of Pathology, UPMC Presbyterian, Pittsburgh, Pennsylvania.
authors.forename: N Paul
authors.initials: NP
authors.lastname: Ohori
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle / Q000379:methods; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D016606:Thyroid Nodule / Q000473:pathology*; D013965:Thyroidectomy / Q000379:methods; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D048493:Proto-Oncogene Proteins B-raf
keywords: incidental carcinoma; molecular; mutation; papillary thyroid carcinoma; size; thyroid nodule