Aetiology of pleural effusions
| Pleural effusions | Number of patients | ||
| Total | With | Without | |
| Neoplastic pleural involvement | |||
| Total | 247 | 126 | 121 |
| Benign | 95 | 0 | 95 |
| Non-inflammatory | 58 | 0 | 58 |
| Congestive heart failure | 42 | 0 | 42 |
| Liver cirrhosis | 6 | 0 | 6 |
| Irritation, others* | 9 | 0 | 9 |
| Nephrotic syndrome | 1 | 0 | 1 |
| Inflammatory | 37 | 0 | 37 |
| Purulent pleurisy/empyema | 21 | 0 | 21 |
| Tuberculous pleurisy | 16 | 0 | 16 |
| Malignancy-associated | 152 | 126 | 26 |
| Carcinomas | 130 | 106 (68) | 24 (13) |
| Lung | 100 | 81 (51) | 19 (11) |
| Adenocarcinoma | 57 | 48 (34) | 9 (9) |
| Squamous cell | 20 | 14 (6) | 6 (1) |
| Large cell | 7 | 7 (4) | 0 |
| Small cell | 16 | 12 (7) | 4 (1) |
| Breast | 10 | 10 (6) | 0 |
| Colorectal | 7 | 6 (6) | 1 (1) |
| Ovarian | 4 | 4 (1) | 0 |
| Gastric | 2 | 1 (1) | 1 (1) |
| Cervical | 2 | 2 (2) | 0 |
| Pancreatic | 1 | 1 (1) | 0 |
| Renal | 1 | 0 | 1 |
| Prostatic | 1 | 0 | 1 |
| Gall bladder | 1 | 1 | 0 |
| Uterine choriocarcinoma | 1 | 0 | 1 |
| Malignant mesothelioma | 17 | 17 | 0 |
| Other malignancies† | 5 | 3 | 2 |
Neoplastic cases are listed also by presence or absence of pleural involvement, and proportion of them producing carcinoembryonic antigen (≥5 ng/mL) is shown in parentheses.
*Pleural thickening: two cases.
†Lymphoma: three cases, melanoma: two cases.