PATHOLOGY OF MALIGNANT MESOTHELIOMA

The diagnosis of malignant mesothelioma can pose several problems to t he surgical pathologist. First, the morphological appearances of the t umour are known to be diverse with mimicry of a range of both reactive and neoplastic conditions. Second, due to the relative inaccessibilit y of the serosa, biopsy material is often scanty and fragmentary, prod ucing a plethora of interpretive ambiguities. Third, adjunct technique s such as mucin histochemistry and immunohistochemistry, whilst useful in excluding malignant mesothelioma have little role in confirming th e diagnosis. The accurate diagnosis of diffuse malignant mesothelioma is important for two reasons: (1) In relation to prognosis as it has a n almost invariable fatal outcome, which contrasts with the other meso thelial neoplasms such as the benign adenomatoid tumour and the border line malignant tumours, namely the well-differentiated papillary mesot helioma and multicystic mesothelioma; (2) In relation to occupational- related compensation claims following asbestos exposure. This review s ummarizes the aetiology of asbestos-induced neoplasia, possible mechan isms of tumour development and highlights potential diagnostic pitfall s.