What is the most common histology of peripheral primary lung cancer?

What is the most common histology of peripheral primary lung cancer?

• A. Adenocarcinoma
• B. Squamous cell
• C. Small cell
• D. Large cell

Answer: (A)

Adenocarcinoma is the most common histology of peripheral primary lung cancer because these tumors originate from glandular cells in the distal airways and alveolar tissue, leading to a peripheral, nodular growth pattern. It has become the prevalent type overall, often seen in nonsmokers or light smokers, and tends to form peripherally rather than in the central airways. In contrast, squamous cell and small cell carcinomas typically arise centrally in the major airways, making them less likely to present as peripheral lesions, while large cell carcinoma is less common and serves more as a broad, less specific category.

Adenocarcinoma is the most common histology of peripheral primary lung cancer because these tumors originate from glandular cells in the distal airways and alveolar tissue, leading to a peripheral, nodular growth pattern. It has become the prevalent type overall, often seen in nonsmokers or light smokers, and tends to form peripherally rather than in the central airways. In contrast, squamous cell and small cell carcinomas typically arise centrally in the major airways, making them less likely to present as peripheral lesions, while large cell carcinoma is less common and serves more as a broad, less specific category.