[Pathology of primary tumours of the pleura].

In the WHO classification, pleural tumours of mesothelial and mesenchymal origin as well as lymphoproliferative disorders are distinguished, with malignant mesotheliomas forming the most common primary pleural tumour. Histologically, a prognostically relevant differentiation between epitheloid (40-60 %), sarcomatoid (20-30 %), and biphasic mesotheliomas (20-30 %) is made. Besides other rare primary tumours of the pleura, the differential diagnoses of malignant mesotheliomas comprise carcinomatous pleuritis of intra- and extrapulmonary malignancies. Especially in early tumour stages, the differentiation from reactive pleural changes requires a close interdisciplinary cooperation with a careful correlation between histopathological findings and clinical presentation.