Alternate Test Names:
TTF1; Thyroid transcription factor 1

Methodology: IHC

Clinical Significance:
Identifies: A nuclear transcription factor that is expressed in a very high percentage of lung and thyroid carcinomas. In lung carcinomas, it is expressed in both non-neuroendocrine as well as endocrine neoplasms, but only rarely in lung squamous cell carcinomas. It is expressed in all variants of thyroid carcinoma with the exception of anaplastic carcinoma. TTF1 loses its organ specificity in the context of high grade neuroendocrine carcinomas. It can also more uncommonly be expressed in other carcinomas, including those primary to the colorectum and breast.

Subcellular Localization: Nuclear

Organ: Lung, Thyroid

Disease State: Adenocarcinoma, Carcinomas of Unknown Primary, Mesothelioma vs. Adenocarcinoma, Non Small Cell Lung Carcinoma (NSCLC)

CPT Code(s): 88342 or 88341 (reference only; CPTs may vary)

Turnaround Time: Within 1-2 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Formalin-fixed, paraffin-embedded (FFPE) tissue block or cell block - OR -
• 1 unstained slide for each test requested plus 3-4 additional unstained slides cut at 4µm