Pleural Fluid Cytology Detects Small Cell Carcinoma Transformation in EGFR-Mutant Lung Adenocarcinoma: A Case Report.
Huijun Zhou, Zhengyue He, Zhuo Wang et al.
✦ AI-curated · Sources linked
Case in brief
A 65-year-old woman with EGFR-mutant lung adenocarcinoma experienced a massive pleural effusion after initially responding to icotinib. Cytological analysis of the pleural fluid identified tumor cells indicative of small cell carcinoma, confirmed by immunohistochemistry. Molecular testing revealed the persistence of the original EGFR mutation, suggesting clonal evolution. This case highlights the utility of pleural fluid analysis in detecting histological transformation.
Diagnostic / clinical pearl
Cytological examination of pleural fluid can effectively identify small cell carcinoma transformation in patients with EGFR-mutant lung adenocarcinoma, aiding in the assessment of acquired resistance to EGFR-TKIs.
Why it matters
This case underscores the importance of integrating cytological and molecular analyses in managing lung adenocarcinoma, particularly when traditional tissue biopsies are challenging.