Coarse pleural calcification in a mesothelioma patient raises the possibility of a rare tumour subtype: osteoblastic sarcomatoid mesothelioma.

It is often suggested that calcification seen in association with pleural thickening implies benign disease. However, we present a case of a patient presenting with coarse pleural calcification associated with a pleural effusion and thickening, which following biopsy was shown to represent osteoblastic sarcomatoid mesothelioma. We describe the imaging features associated with this and differentiate these findings from those seen with benign pleural calcification. Similarities are drawn to other rare cases described in the literature.