| Group 1 | Group 2 | ||
| Malignant | |||
| adenocarcinoma | 19 | 6 | |
| squamous cell carcinoma | 5 | 1 | |
| small cell carcinoma | 5 | 0 | |
| malignant mesothelioma | 0 | 1 | |
| metastases | 4 | 1 | |
| Benign | |||
| epithelioid cell granuloma | 2 | 0 | |
| non-specific benign | 5 | 1 | |