title: Expression of Cytokeratin-19 and Thyroperoxidase in Relation to Morphological Features in Non-Neoplastic and Neoplastic Lesions of Thyroid.
abstract: BACKGROUND
  Thyroperoxidase (TPO) is a protein involved in thyroid hormone synthesis. TPO gene suppression and mutation were involved in thyroid tumours. CK-19 plays important role in the structural integrity of epithelial cells. Reduced TPO expression with increased CK-19 immunoreactivity has been implicated as a marker for differentiating non neoplastic and neoplastic thyroid lesions.
  
  
  OBJECTIVE
  To study the histopathological features of thyroid lesions and to evaluate the diagnostic role of thyroperoxidase and CK-19 in non-neoplastic and neoplastic thyroid lesions.
  
  
  METHODS
  Prospective observational study of 65 thyroid specimens was studied for detailed histopathological examination and Expression of Immunohistochemical Markers Cytokeratin-19 (CK-19) and Thyroperoxidase.
  
  
  RESULTS
  TPO IHC marker was expressed by non-neoplastic and benign lesions of thyroid but not in malignancy. CK-19 was expressed 100% in papillary carcinoma of thyroid and its variants, focal and weak staining noted in goitre and hyperplastic areas.
  
  
  CONCLUSIONS
  Most of the non-neoplastic and neoplastic lesions were diagnosed based on histopathological features. When the histopathological diagnosis are equivocal, immunohistochemical markers aids in diagnosing malignancy. Diffuse and strong TPO expression indicates non-neoplastic thyroid lesions whereas diffused and strong CK-19 expression indicates thyroid malignancy.
authors: Post Graduate Student, Department of Pathology, Shri Sathya Sai Medical College and Research Institute , Ammapettai, Kancheepuram, Tamil Nadu, India .
authors: Hemanathan
authors: H
authors: Guhanandam
authors: Assistant Professor, Department of Pathology, Shri Sathya Sai Medical College and Research Institute , Ammapettai, Kancheepuram, Tamil Nadu, India .
authors: Revathishree
authors: R
authors: Rajamani
authors: Professor, Department of Pathology, Shri Sathya Sai Medical College and Research Institute , Ammapettai, Kancheepuram, Tamil Nadu, India .
authors: Naseen
authors: N
authors: Noorunnisa
authors: Professor, Department of Pathology, Shri Sathya Sai Medical College and Research Institute , Ammapettai, Kancheepuram, Tamil Nadu, India .
authors: Manimaran
authors: M
authors: Durairaj
keywords: Multinodular goitre; Papillary carcinoma; Thyroid disorders