title: Coexistence of papillary thyroid cancer with Hashimoto thyroiditis.
abstract: OBJECTIVE
  Conflicting data have been reported with regard to Hashimoto thyroiditis (HT) and risk of malignancy. The aim of this study was to evaluate coexistence of papillary thyroid cancer (PTC) with HT.
  
  
  METHODS
  This is a retrospective cohort study in which HT was diagnosed in 452 (F/M ratio = 405:47, median age 53.5 ± 12.1 years) of 7,545 patients qualified for thyroidectomy throughout the years 2002 to 2010. Pathological reports were reviewed to identify prevalence of PTC in HT vs. non-HT patients.
  
  
  RESULTS
  PTC was diagnosed in 106 of 452 (23.5 %) HT patients vs. 530 of 7,093 (7.5 %) non-HT patients (p < 0.001). Metastases to level VI lymph nodes were observed in 81 of 106 (76.4 %) patients with PTC in HT vs. 121 of 530 (22.8 %) patients with PTC in non-HT disease (p < 0.001).
  
  
  CONCLUSIONS
  HT was associated with a threefold increase of PTC prevalence as compared to other non-HT thyroid diseases, and the spread of PTC to level VI lymph nodes was four times more frequent in HT than in non-HT patients.
authors.affiliation: Department of Endocrine Surgery, 3rd Chair of General Surgery, Jagiellonian University Medical College, 37 Prądnicka Street, 31-202, Krakow, Poland. okont@mp.pl
authors.forename: Aleksander
authors.initials: A
authors.lastname: Konturek
authors.forename: Marcin
authors.initials: M
authors.lastname: Barczyński
authors.forename: Wojciech
authors.initials: W
authors.lastname: Wierzchowski
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Stopa
authors.forename: Wojciech
authors.initials: W
authors.lastname: Nowak
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001707:Biopsy, Needle; D002277:Carcinoma / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D050031:Hashimoto Disease / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D015996:Survival Rate; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods