Which lung cancer type is typically central in location and strongly associated with smoking?

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

Answer: (D)

This item hinges on how lung cancer types relate to where they occur in the lung and their smoking associations. Squamous cell carcinoma typically grows in the central, proximal airways—the main bronchi—so it forms a central mass and can cavitate from necrosis. Its strong link to tobacco smoke reflects a pathogenesis where smoking induces chronic injury and squamous metaplasia of the bronchial epithelium, progressing to dysplasia and then invasive carcinoma. By contrast, adenocarcinoma usually appears peripherally in the lung and is the most common type among nonsmokers. Large cell carcinoma is also often peripheral and undifferentiated, while adenosquamous carcinoma contains both glandular and squamous features but isn’t as characteristically central as pure squamous cell carcinoma. So the combination of a central location and a strong smoking association best fits squamous cell carcinoma.