Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist.

Objectives: In Japan, benign asbestos pleural effusion (BAPE) has been eligible for industrial accident compensation since 2003 as an asbestos-related disease despite the lack of good criteria. We compiled a criteria into a checklist of essential items and for excluding other diseases inducing pleural effusion as a diagnosis process.

Method: Thoracentesis was performed in order to confirm the presence of pleural effusion at the initial diagnosis, and 105 suspected BAPE patients were retrospectively examined. We complied a checklist comprising the following diagnostic items: (a) occupational asbestos exposure; (b) confirmation of exudate of pleural effusion; (c) exclusion of pleural effusion with malignant tumors based on negative results of CEA and hyaluronic acid, and cytology of pleural effusion; (d) exclusion of rheumatic, bacterial, and tuberculous pleuritis; (d) radiological findings for exclusion of malignancies; and (e) histopathological findings based on thoracoscopy that exclude malignancies (when thoracoscopy was not performed, there was confirmation that no malignancies were present during 3-month follow-up observation). Cases that satisfied all items were defined as BAPE.

Results: Among the 105 suspected cases, there were five cases that had no occupational asbestos exposure; six cases in which transudate of on pleural effusion; one case each of rheumatoid pleuritis and tuberculous pleuritis; and five cases of pleural mesothelioma based on chest radiography and histopathological findings within 3 months after initial diagnosis. Therefore, we excluded 18 cases from the 105 candidates and determined 87 cases of BAPE.

Conclusion: We consider that six items described above are suitable for diagnosing BAPE.