Question

Which tumor is positive for TTF-1?

• A. Squamous Cell Carcinoma (Sq)
• B. Small Cell Carcinoma (Small)
• C. Adenocarcinoma (Adeno Ca)
• D. Carcinoid

Hint:

TTF-1 is typically used as a marker for lung adenocarcinoma and small cell lung carcinoma, but it is most strongly associated with adenocarcinomas.

Answer 1

The Correct Option is C

TTF-1, or Thyroid Transcription Factor-1, is a nuclear protein that serves as an important immunohistochemical marker in pathology. It is commonly used to help identify and classify different types of tumors. In the context of lung cancers, TTF-1 is a reliable marker for differentiating between various histological types.

TTF-1 positivity is particularly significant in the diagnosis of lung adenocarcinomas and small cell lung carcinomas. Among the options provided:

• Squamous Cell Carcinoma (Sq): Squamous cell carcinoma of the lung is typically negative for TTF-1.
• Small Cell Carcinoma (Small): Small cell lung carcinoma is usually positive for TTF-1, but it is not the primary focus in this question.
• Adenocarcinoma (Adeno Ca): Adenocarcinoma of the lung is characteristically positive for TTF-1. This marker is instrumental in confirming the diagnosis of primary lung adenocarcinoma.
• Carcinoid: Carcinoid tumors may be positive for TTF-1; however, this is not as definitive as in adenocarcinomas.

Thus, the tumor that is specifically noted for its TTF-1 positivity in the provided options is Adenocarcinoma (Adeno Ca).