Chinese Academy of Sciences Apr 20 2026 Pleural effusion cytology is already used in cancer diagnosis, especially in metastatic settings, but its sensitivity can be limited. Tumor cells are easily masked by overwhelming numbers of background blood cells, and cluster structures may be disrupted during processing. Immune-affinity approaches can detect malignant tumor cells (MTCs), yet they may damage cells, dissociate malignant tumor cell clusters (MTCCs), and mask surface biomarkers with