US and MR imaging features of benign cystic mesothelioma of the liver: A diagnostic dilemma

Cystic mesotheliomas are benign neoplasms, often seen in the parietal and visceral peritoneum, omentum and pelvic organs, and are exceedingly rare in the liver. It is however important to be familiar with the radiological findings of this tumour because the signal-intensity and enhancement pattern of this tumor are unusual and not typical for any of the more frequently seen mass lesions. In our patient, characteristic imaging findings on dynamic contrast-enhanced MRI and histopathological confirmation with appropriate immunohistochemical markers facilitated a correct diagnosis. We herein describe the clinical, imaging and histopathological features, pathogenesis, differential diagnosis and treatment of benign cystic mesothelioma involving posterior segment of the right lobe of the liver.