Which form of lung cancer presents with a pleural effusion?

• A. Small Cell
• B. Large Cell
• C. Adenocarcinoma
• D. B & C

Answer: (D)

Malignant pleural effusion happens when cancer cells reach and irritate the pleural space, or when lymphatic drainage is blocked, leading to fluid buildup. Among lung cancers, adenocarcinoma and large cell carcinoma are more likely to involve the pleura because they tend to arise peripherally and spread to nearby surfaces, including the pleural lining. Adenocarcinoma specifically often appears in the lung periphery and has a tendency to metastasize to pleural surfaces, making effusions a common presenting feature. Large cell carcinoma is also typically peripheral and aggressive, with a higher chance of invading the pleura.

Small cell lung cancer, while aggressive and prone to early metastasis, usually originates centrally and presents with symptoms related to mass effect or paraneoplastic processes rather than as a pleural effusion at presentation. So the combinations of adenocarcinoma and large cell carcinoma best fit the presentation of a pleural effusion.