title: Impact of lymphocytic thyroiditis on incidence of pathological incidental thyroid carcinoma.
abstract: The purpose of this study was to investigate the impact of lymphocytic thyroiditis on incidence of incidental thyroid cancers.
  
  
  
  We conducted a retrospective review of 713 consecutive patients who underwent thyroidectomies. Incidental thyroid cancer was defined as an unexpected cancer discovered on pathological examination outside the index nodule undergoing preoperative cytology.
  
  
  
  We excluded 65 cases because of preoperative diagnosis of thyroid cancer, and 68 because of nonincidental cancer within the index nodule. Among the remaining 580 cases, there were 43 cases (7.4%) of incidental thyroid cancers. Incidental thyroid cancers were significantly associated with moderate/severe lymphocytic thyroiditis (relative risk = 2.5; p = .03). Sixteen of 56 patients with moderate/severe lymphocytic thyroiditis had Graves' disease, none of whom had incidental thyroid cancer. The risk of incidental thyroid cancer associated with moderate/severe lymphocytic thyroiditis was significantly higher in non-Graves' than patients with Graves' disease (p = .05).
  
  
  
  The risk of incidental thyroid cancer is significantly increased in patients with moderate/severe lymphocytic thyroiditis. Moderate/severe lymphocytic thyroiditis associated with Graves' disease seems to have a lower risk of incidental thyroid cancer. © 2016 Wiley Periodicals, Inc. Head Neck 39: 122-127, 2017.
authors: School of Medicine, University College Cork, Cork, Ireland, United Kingdom.
authors: Eric
authors: E
authors: Farrell
authors: Department of Pathology, Cork University Hospital, Cork, Ireland, United Kingdom.
authors: Cynthia
authors: C
authors: Heffron
authors: Department of Endocrinology, South Infirmary Victoria University Hospital, Cork, Cork, Ireland, United Kingdom.
authors: Matthew
authors: M
authors: Murphy
authors: Department of Otolaryngology - Head and Neck Surgery, South Infirmary Victoria University Hospital, Cork, Cork, Ireland, United Kingdom.
authors: Gerard
authors: G
authors: O'Leary
authors: Department of Otolaryngology - Head and Neck Surgery, South Infirmary Victoria University Hospital, Cork, Cork, Ireland, United Kingdom.
authors: Patrick
authors: P
authors: Sheahan
mesh_terms: D002291:Carcinoma, Papillary / Q000453:epidemiology*; D005260:Female; D006111:Graves Disease / Q000150:complications / Q000473:pathology; D006801:Humans; D015994:Incidence; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000453:epidemiology*; D013965:Thyroidectomy; D013967:Thyroiditis, Autoimmune / Q000150:complications* / Q000473:pathology* / Q000601:surgery
keywords: Graves' disease; Hashimoto's thyroiditis; lymphocytic thyroiditis; papillary carcinoma; thyroid cancer