Among bronchogenic carcinomas, which histologic type is most common overall?

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

Answer: (A)

Adenocarcinoma is the most common histologic type of bronchogenic carcinoma overall. It tends to arise from glandular or mucin-producing cells and grows peripherally in the lung, which helps explain why it has become the leading form in many populations, including both smokers and nonsmokers. This peripheral location and its association with nonsmokers and women contribute to its higher overall frequency.

By contrast, squamous cell carcinoma is more often central and strongly linked to smoking, while small cell carcinoma is also smoking-related and highly aggressive but accounts for a smaller share overall. Large cell carcinoma is less common and typically poorly differentiated. Therefore, adenocarcinoma remains the most frequent type overall.