TTF-1

Thyroid transcription factor-1 (TTF-1) belongs to a family of homeodomain transcription factors and is selectively expressed in thyroid, lung and diencephalon. TTF-1 is considered as a reliable marker for differentiating primary adenocarcinomas of the lung from metastatic lung cancers.

Recommended Controls

The criteria for acceptable staining is moderate to strong nuclear staining reaction in type II pneumocyte and the Clara cells lining the alveolar walls; negative or weak nuclear staining reaction in the epithelial cells of the respiratory ducts (if present). The recommended positive controls to use is appendix which will be negative and lung as the positive control. A lung adenocarcinoma will be a high expressor.

Appendix

Lung Adencocarcinoma

Normal lung

Pneumocytes in normal lung

Disclaimer

These methods are intended as a guide only. Laboratories that wish to implement these methods should perform internal validation/verification prior to use. The RCPAQAP does not make any claim or warranty for the accuracy or performance of these methods.