A Canadian experience of the pathological diagnosis of diffuse mesothelioma.

A review of 398 pleural and peritoneal tumours suggests that diffuse mesothelioma was probably present in 50-60%. However, objective assessment was frequently impeded by serious deficiencies in data or material, which affect the diagnostic grading of cases seen by panels. Observer variation in diagnosis also remains a significant problem. The value of panels for diagnosis could be greatly increased by the provision of adequate data/material and by meetings.