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Lung Cancer Clubbing — RACP Adult Medicine MCQ

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EasyRespiratoryLung Cancer ClubbingRACP Adult Medicine

A 55-year-old man with a 40-pack-year smoking history presents with weight loss and clubbing. CXR shows a large right hilar mass. CT confirms a 5 cm central lung mass with mediastinal lymphadenopathy. Biopsy shows squamous cell carcinoma. What is the most common pulmonary cause of clubbing?

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Correct answer: E — Lung cancer

Lung cancer (particularly squamous cell carcinoma and adenocarcinoma) is the most important cause of NEW-ONSET clubbing in an adult smoker. It may present with hypertrophic pulmonary osteoarthropathy (HPOA — periostitis causing painful swollen joints). Any new clubbing in a smoker warrants urgent investigation for malignancy. Other pulmonary causes: bronchiectasis (most common benign pulmonary cause), IPF, CF, empyema. Non-pulmonary causes: IE, congenital cyanotic heart disease, IBD, cirrhosis.

Reference: Cancer Council Australia – 2024; eTG Respiratory 2024