Adenocarcinoma

Question 1

What is the most common type of NSCLC?

Answer 1

Adenocarcinoma

Question 2

What is the % of NSCLC is adenocarcinoma?

Answer 2

> 50%

Question 3

What are the four histologic subtypes of adenocarcinoma?

Answer 3

Acinar, papillary, AIS, and solid with mucous formation

Question 4

What are the typical stains on pathology for adenocarcinoma, and are they positive or negative?

Where does adenocarcinoma typically present in the chest?

Answer 4

Cytokeratin 7 (CK7) +
Cytokeratin 20 (CK20) -
Majority of pulmonary adeno is thyroid transcription factor (TTF-1) +

Adenocarcinoma typically presents in the periphery of the chest.

Question 5

Describe AIS morphologically in the lungs i.e. how it looks inside the lungs?

Answer 5

AIS typically spreads along alveolar septae. Typically lacks invasive growth.

Question 6

What two forms of AIS are there? Describe the staining description of each?

Answer 6

AIS presents as mucinous (TTF-1 negative, rarely having EGFR mutations) and nonmucinous (positive for TTF-1).

Question 7

What mutations are always testing in adenocarcinoma lung cancer?

Answer 7

ALK and EGFR