Mucin lakes or perforation

We are reporting two cases with similar appearances on post chemo radiotherapy MRI scan of the mucinous adenocarcinoma. There was high signal on T2-weighted sequences of the mucin pools within and beyond the rectal wall. Does this imply that wall tissues become less resistant to cancer pools intrusion after chemo radiation? Does the high intramural pressure have an impact on the protrusion of the cancer pools beyond the muscularis propria? Final histology reports differ from predicted MRI staging. It highlights the difficulty of the final MRI staging and outcome for mucinous adenocarcinomas. The presence of acellular mesothelial reaction, acellular mucin pools and inflammation extending to the serosal surface causes considerable confusion and may result in over staging or under staging of mucinous adenocarcinoma. Pathogenesis and prediction of the mucin lakes behaviour prior and post chemoradiotherapy is unclear and requires future study but may impact surgical management.