Case of the week · 9 October 2026
Three months of “TB” treatment and a pleural effusion
A 48-year-old schoolteacher who has never smoked was started on antituberculous treatment for a right-sided effusion 3 months ago, without sputum or fluid microbiology. She is more breathless and has lost 6 kg. Repeat pleural tap: lymphocytic exudate, ADA 16 U/L. CT (schematic) shows the effusion with nodular pleural thickening.
1. What are the next two diagnostic steps?
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Repeat pleural cytology with a cell block (yield rises with a second and third sample) and, if negative, thoracoscopic pleural biopsy. Send the same material for TB tests. A low ADA makes TB unlikely.
2. Cytology shows TTF-1-positive adenocarcinoma. What must be done before any treatment?
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Stage (contrast CT, brain MRI; PET-CT if it changes management) and send the cell block for NGS (EGFR, ALK, ROS1, RET, MET, BRAF and others) plus PD-L1. Do not start immunotherapy while the driver result is pending.
3. NGS shows an EGFR exon 19 deletion. What are the first-line options?
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Osimertinib, osimertinib with platinum–pemetrexed (now with an overall-survival gain), or amivantamab with lazertinib. Where cost is the barrier, gefitinib with pemetrexed–carboplatin (Tata Memorial trial) is an evidence-based alternative.
- Unproven TB plus a low-ADA exudate is cancer until shown otherwise.
- Pleural fluid cell blocks are often enough for NGS.
- Choose first-line EGFR therapy by disease burden, brain metastases, toxicity and cost.
Trial behind this case: FLAURA2 final overall survival
Question: Does adding platinum–pemetrexed to first-line osimertinib prolong life?
Result: Yes: median overall survival 47.5 vs 37.6 months (HR 0.77), with more haematological toxicity.
Indian practice: Most benefit in brain metastases and L858R; weigh extra visits and cost.
Read more: Lung cancer mini review · MCQ bank