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.