• All IHC stains will include a positive control tissue

• TTF-1 is present in normal thyroid and neoplastic thyroid tumors such as papillary carcinoma
• TTF-1 is present in the majority of pulmonary adenocarcinomas (73-76%) and pulmonary small cell carcinomas (83%)
• A smaller proportion of large cell undifferentiated lung carcinomas (26%) stain for TTF-1.
• Squamous cell carcinomas of the lung do not stain for TTF-1
• Malignant mesotheliomas are negative for TTF-1
• Cytoplasmic staining for TTF-1 can be useful in identifying hepatocellular carcinoma
• Papillary nasopharyngeal carcinomas have been reported to stain for this marker
• A small proportion of breast cancers will stain for this marker (2.4% of 546 primary breast cancers in one study)
• Small cell carcinomas of the prostate are positive for TTF-1
• Colorectal adenocarcinoma (including metastatic to the lung) can show diffuse, moderate to strong TTF-1 positivity. It is estimated up to 3% of colorectal adenocarcinomas will be TTF-1 positive with the TTF-1 clone we use (Dako clone 8G7G3/1). While the majority of these cases will demonstrate weak TTF-1 positivity, diffuse, strong positivity can occur
• Other tumors have been rarely reported to be TTF-1 positive (nuclear), and include cholangiocarcinoma, endometrial, ovarian, gastric/esophageal, cervical, pancreatic ductal, urothelial, hepatocellular, adenoid cystic, other salivary gland carcinomas, and adrenal cortical carcinoma. Typically, these tumors will show expression in a small fraction of tumor cells.

Submit a formalin-fixed, paraffin embedded tissue block

.

Formalin-fixed, paraffin embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• Reacts with a transcription factor that is expressed selectively in the thyroid, lung, and diencephalon
• In the lung, TTF-1 is present in Type II Cells and Clara Cells and is important in the activation of pulmonary-specific differentiation genes
• In thyroid, TTF-1 is present in follicular epithelial cells
• TTF-1 is expressed early in the embryogenesis of thyroidal and respiratory epithelium, arising from endoderm of the foregut
• TTF-1 expression has also been found in some endometrial and endocervical carcinomas ⁸
• Cytoplasmic staining for TTF-1 with this clone can be seen in hepatocellular carcinoma

 Staining patterns

• Nuclear staining in lung, thyroid, and papillary nasopharyngeal carcinoma
• Cytoplasmic staining in hepatocellular carcinoma

References

1. Holzinger A, et. Al. Monoclonal Antibody to Thyroid Transcription Factor – 1: Production, Characterization, and Usefulness in Tumor Diagnosis. Hybridoma, Vol. 15 (1): 49, 1996.
2. Harlamert HA et al. Distinguishing Primary Lung Adenocarcinomas from Metastatic Breast Adenocarcinomas in Cytology Specimens using TTF-1 and Cytokeratins 7 and 20. Mod Path, 10(1): A185, 1997.
3. Anderson SS, et al. Thyroid Transcription Factor -1 (TTF-1) is a More Sensitive Lung Carcinoma Marker than Surfactant. ApoA1. Lab Invest, 78(1): 171A (1001), 1998.
4. Bohinski RJ, et al. Determination of Lung as the Primary Site of Cerebral Metastatic Adenocarcinomas using Monoclonal Antibody to Thyroid Transcription Factor -1. J Neuro-Oncology, 1998.
5. Bejarano P.A., et al. Surfactant Proteins and Thyroid Transcription Factor -1 in Pulmonary and Breast Carcinomas. Mod Path, 9(4): 445, 1996.
6. Khoor A, et al. Utility of Surfactant Protein B Precursor and Thyroid Transcription Factor – 1 in Differentiating Adenocarcinomas of the Lung from Malignant Mesothelioma. In press.
7. Dilorecto C, et al. TTF-1 Protein Expression in Pleural Malignant Mesotheliomas and Adenocarcinomas of the Lung. Cancer, 124(1): 73-78, 1998.
8. Siami K et al: Transcription factor-1 expression in endometrial and endocervical adenocarcinomas. Am J Surg Pathol 2007, 31 (11) 1759-1763.
9. Pineda-Daboin K et al: Nasopharyngeal adenocarcinomas: a clinicopathologic study of 44 cases including immunohistochemical features of 18 papillary phenotypes. Annal Diag Pathology 9(2005):189-192.
10. Lei J et al: Cytoplasmic Staining of TTF-1 in the Differential Diagnosis of Hepatocellular Carcinoma vs Cholangiocarcinoma and Metastatic Carcinoma of the Liver. Am J Clin Pathol 2006;125:519-525.
11. Goldstein RJ , Gown AM, Schnitt SJ: Thyroid transcription factor-1 expression in breast carcinomas. Am J Surg Pathol 2010 Dec;34(12):1881-5.
12. Wang W, Epstein JI. Small cell carcinoma of the prostate. A morphologic and immunohistochemical study of 95 cases. Am J Surg Pathol. 2008 Jan;32(1):65-71. PubMed PMID: 18162772.
13. Conner JR, Hornick JL: Metastatic carcinoma of unknown primary: diagnostic approach using immunohistochemistry. Adv Anat Pathol 2015;22:149-167.