Biphasic malignant mesothelioma cases with osseous differentiation and long survival: A review of the literature

SummaryThis report describes two cases of diffuse biphasic malignant mesothelioma with osseous differentiation and long survival. Two male patients aged 66 and 54 years presented with chest pain, bloody pleural effusions, and diffuse and nodular pleural thickening. They both had a history of prolonged asbestos exposure. Sarcomatoid and epithelioid areas were identified on histopathological examination. In addition, there were foci of ossification. Epithelioid tumor cells as well as benign osteoclasts within the ossification reacted positively for cytokeratin 5/6, whereas sarcomatoid areas were negative. Both patients survived 39 and 69 months, respectively. To our knowledge, these two cases with biphasic malignant mesothelioma and osseous differentiation with long survival are the first to be described from Central Anatolia.