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Malignant Pleural Effusion — RACP Adult Medicine MCQ

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EasyRespiratoryMalignant Pleural EffusionRACP Adult Medicine

A 72-year-old woman with known metastatic breast cancer presents with progressive dyspnoea. CXR shows a large right pleural effusion. Pleural fluid analysis: protein 42 g/L, LDH 350 U/L (serum LDH 200 U/L), glucose 3.5 mmol/L, pH 7.35. Cytology shows malignant cells. What is the most likely diagnosis?

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Correct answer: C — Malignant pleural effusion

Exudative effusion (Light criteria met: pleural/serum LDH ratio >0.6) with positive cytology for malignant cells in a patient with known breast cancer is a malignant pleural effusion. Management is therapeutic thoracentesis for symptom relief, with consideration of indwelling pleural catheter or talc pleurodesis for recurrent symptomatic effusions.

Reference: eTG Respiratory – 2024 – Malignant Pleural Effusion; BTS 2023