[Morphology, diagnosis and differential diagnosis of mesothelioma]

Forty cases of mesothelioma biopsied and autopsied from 1961 to 1985 were studied and analysed as to their morphology, diagnosis and differential diagnosis. Mesothelioma had complex histologic types. The tumor cells varied in size and shape and were characterized morphologically by the coexistence of biphasic differentiation, adenoid and microvilli formation. The pathologic diagnosis is made according to the feature of biphasic differentiation, or coexistence of epithelioid and spindle tumor cells. It should be emphasized that the tissue sections are taken from multiple areas. Usually, the correct diagnosis is made in correlation to the clinical manifestations. For difficult cases of the diffuse mesothelioma, electron microscopy is needed to differentiate from metastatic adenocarcinoma and spindle cell sarcoma etc.