PT - JOURNAL ARTICLE AU - Butnor, Kelly J AU - Pavlisko, Elizabeth N AU - Sporn, Thomas A AU - Roggli, Victor L TI - Malignant peritoneal mesothelioma and Crohn disease AID - 10.1136/jclinpath-2016-203945 DP - 2017 Mar 01 TA - Journal of Clinical Pathology PG - 228--232 VI - 70 IP - 3 4099 - http://jcp.bmj.com/content/70/3/228.short 4100 - http://jcp.bmj.com/content/70/3/228.full SO - J Clin Pathol2017 Mar 01; 70 AB - Aims Mesothelial reaction simulating peritoneal diffuse malignant mesothelioma (MM) has been reported in the setting of Crohn ileitis. To our knowledge, peritoneal MM arising in patients with inflammatory bowel disease (IBD) has not been reported. The purpose of this study is to report the clinicopathological characteristics of patients with peritoneal MM and IBD.Methods A database of approximately 3800 MM was reviewed for cases of MM in patients with IBD.Results Three patients (0.08%) with peritoneal MM and Crohn disease (CD) were identified, including two women and one man ranging in age from 56 to 65 years. All had a long-standing history of diarrhoea and an established diagnosis of CD of 3 years or greater duration. Two had epithelial MM and one had biphasic MM. Only one had documented asbestos exposure.Conclusions Peritoneal MM occurs rarely in patients with IBD, but interestingly, has only been observed in the setting of CD and not in patients with ulcerative colitis. Chronic inflammation has been associated with the development of MM in rare instances and these three cases suggest that CD with transmural inflammation may also be a precursor. The precise role of CD-related transmural inflammation in the carcinogenesis of peritoneal MM remains to be determined.