Which lung cancer is the most common in women and nonsmokers and tends to be located peripherally?

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

Answer: (B)

Adenocarcinoma is the lung cancer type most commonly seen in women and in nonsmokers, and it tends to arise in the peripheral parts of the lung. This tumor originates from glandular-type cells in the bronchial/alveolar epithelium and often forms gland-like or mucin-producing patterns, which helps explain why it shows up as a peripheral, often smaller nodule on imaging. The epidemiology is distinct from other major types: while heavy smoking is a major risk factor for many lung cancers, adenocarcinoma has the strongest association with never-smokers and with women.

In contrast, small cell carcinoma is a neuroendocrine tumor that is strongly linked to smoking and typically grows centrally near the major airways. Squamous cell carcinoma is also commonly central and linked to smoking, often with cavitation. Large cell carcinoma can be peripheral, but it lacks the same clear association with never-smokers or women and is less characteristic in location and differentiation.