Multilocular peritoneal inclusion cysts (benign cystic mesothelioma): a case report.

We report a case of a rare lesion, a multilocular peritoneal inclusion cyst (MPIC), and describe in detail its appearance on MRI. A young woman with pain of the lower abdomen underwent surgical removal of a mass that was histologically diagnosed as an MPIC. The characteristic MRI features were a multilocular cystic mass with thin septa in the pelvic cavity, located both anterior and posterior to the uterus and the adnexa, showing hypointensity of the cyst contents on T1 images and variable hyperintense signals on T2 images.