A 35 year old female non-smoker has adeno-carcinoma of lung. Which one of the following immunohistochemical marker is used for detection of adenocarcinoma of lung?
**Core Concept**
The diagnosis of lung adenocarcinoma involves the identification of specific immunohistochemical markers that distinguish it from other types of lung cancer. **Adenocarcinoma** is a type of non-small cell lung cancer, and its diagnosis relies on the expression of certain proteins.
**Why the Correct Answer is Right**
The correct answer is related to the expression of a specific protein that is commonly found in adenocarcinoma of the lung. **TTF-1 (Thyroid Transcription Factor 1)** is a marker that is often used to identify adenocarcinoma of the lung, as it is expressed in the nuclei of adenocarcinoma cells.
**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because it is not a specific marker for adenocarcinoma of the lung.
**Option B:** is incorrect because it is not related to lung adenocarcinoma.
**Option C:** is incorrect because it is not a marker for adenocarcinoma.
**Option D:** is incorrect because it is not specific for lung adenocarcinoma.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that **TTF-1** is a critical marker for the diagnosis of adenocarcinoma of the lung, especially in small biopsy samples.
**Correct Answer:** D. TTF-1.