title: Expression of p63 and Bcl-2 in Malignant Thyroid Tumors and their Correlation with other Diagnostic Immunocytochemical Markers.
abstract: BACKGROUND
  Bcl-2 is a marker recently studied in thyroid tumours and proposed to have prognostic significance. p63 is expressed in a proportion of papillary thyroid carcinoma cases and may have a role in tumour progression.
  
  
  OBJECTIVE
  To study expression of Bcl2 and p63 in thyroid tumours and correlation of Bcl-2 with diagnostic markers including Thyroglobulin, Calcitonin and Carcinoembryonic antigen.
  
  
  METHODS
  Cytology smears of 35 cases of thyroid cancer were studied over a period of 18 months. In 20 cases histopathology was available. Immunocytochemistry for Bcl-2 and p63 was done, and diagnostic markers were applied as and when required.
  
  
  RESULTS
  p63 showed focal nuclear expression in 46.1% of papillary thyroid carcinoma cases, and was negative in all other tumours. Bcl-2 was positive in 88.9% of follicular carcinomas, 100% of papillary carcinomas and 83.3% of medullary carcinoma cases, and showed focal weak expression in 40% of Anaplastic Carcinoma (ATC) cases, thereby signifying down regulation (p-value = 0.001). There was significant down regulation of Thyroglobulin (Tg) in ATC vs well differentiated follicular derived tumours (p-value ≤ 0.016). Positive correlation was noted between expression of Bcl-2 and Calcitonin (0.93) and Bcl-2 and Carcinoembryonic Antigen (CEA) (0.89), and weak positive correlation (0.65) between Tg and Bcl-2.
  
  
  CONCLUSIONS
  Bcl-2 is downregulated in anaplastic carcinomas as compared to well differentiated thyroid tumours, and shows correlation with differentiation associated tumour antigens. Thus, loss of Bcl-2 was associated with loss of differentiation in thyroid tumours. Anaplastic carcinoma as such is associated with worse prognosis and loss of Bcl-2 may be partly responsible for the same. p63 is specific but less sensitive marker for PTC. Further studies are required to determine the role of Bcl-2 and p63 in thyroid tumours.
authors.affiliation: Assistant Professor, Department of Pathology, Baba Saheb Ambedkar Medical College and Hospital , New Delhi, India .
authors.forename: Ashumi
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Professor and Head of the Department, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Shyama
authors.initials: S
authors.lastname: Jain
authors.affiliation: Professor, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Nita
authors.initials: N
authors.lastname: Khurana
authors.affiliation: Director Professor, Department of Surgery, Lok Nayak Hospital , New Delhi, India .
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Kakar
keywords: Carcinoma; FNAC; Immunocytochemistry