title: Immunohistochemical expression of COX-2 in thyroid nodules.
abstract: BACKGROUND
  Recent evidence indicates that elevated COX-2 expression is associated with the carcinogenesis of numerous neoplasms. In this study, we investigated COX-2 expression in various thyroid specimens in order to elucidate its physiological role in pathologic conditions, and to evaluate the efficiency of COX-2 protein expression as a molecular marker of malignancy in the thyroid gland.
  
  
  METHODS
  COX-2 expression was studied immunohistochemically in 19 papillary carcinomas, 8 follicular carcinomas, 14 follicular adenomas, 2 Hürthle cell carcinomas, 4 Hürthle cell adenomas, 8 nodular hyperplasias, 3 Graves' diseases, 3 Hashimoto's thyroiditis, 2 medullary carcinomas, 1 anaplastic carcinoma, and 20 normal thyroid tissues.
  
  
  RESULTS
  COX-2 staining was not seen in any of the normal thyroid, Graves' disease, or nodular hyperplasia specimens. In contrast, COX-2 staining was observed in all of papillary carcinomas, Hashimoto's thyroiditis, Hürthle cell carcinomas, and Hürthle cell adenomas tissues. Moreover, 7 of 8 follicular carcinomas and 11 of 14 follicular adenomas showed COX-2 staining.
  
  
  CONCLUSIONS
  These results indicate that COX-2 is not useful as a marker of malignancy. Since COX-2 expression was evident in follicular adenomas and in papillary and follicular carcinomas. Thus, the enzyme may be involved in the early process of thyroid tumorigenesis.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Medical College, Cheonan, Korea. ksj1113@schch.co.kr
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jae Hak
authors.initials: JH
authors.lastname: Lee
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Yoon
authors.forename: Ji O
authors.initials: JO
authors.lastname: Mok
authors.forename: Yeo Joo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hyeong Kyu
authors.initials: HK
authors.lastname: Park
authors.forename: Chul Hee
authors.initials: CH
authors.lastname: Kim
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Byun
authors.forename: Kyo Il
authors.initials: KI
authors.lastname: Suh
authors.forename: Myung Hi
authors.initials: MH
authors.lastname: Yoo
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D051546:Cyclooxygenase 2; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis*; D016606:Thyroid Nodule / Q000201:enzymology* / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases