CT differentiation of diffuse malignant peritoneal mesothelioma and peritoneal carcinomatosis

Diffuse malignant peritoneal mesothelioma (DMPM) and peritoneal carcinomatosis (PC) have similar imaging in computer tomography (CT). We aimed to distinguish them.

Computer tomography findings were evaluated in 48 DMPM and 47 PC for the peritoneal, mesenteric, omentum, lymph nodes, viscera infiltration, ascites and pleural plaques.

Two groups had no difference in terms of thickness, clinical manifestation, diameter of lymph nodes, ascites, and viscera infiltration. But they showed differences in the following: Ratio of asbestos exposure in DMPM group was higher. Smooth and irregular peritoneal thickening were more seen in DMPM group; peritoneal nodules were more commonly detected in PC group. Forty-eight cases of peritoneum in DMPM showed mild enhanced, while 14 patients in PC showed severe enhanced. Nodular type of omentum was more common in PC group than in DMPM group; omental cake was more commonly detected in DMPM group. Mesentery involvement was more commonly seen in DMPM group. Location of enlarged lymph nodes in cardiophrenic region was more frequently identified in DMPM, whereas location of enlarged lymph nodes in retroperitoneal region was more frequently identified in PC. Lymph nodes fusion was more frequently visualized in PC. Fixation of the intestinal wall was more common in DMPM. Pleural plaque was more common in DMPM. PC had distant metastasis except primary foci and peritoneum. In PC, tumor origins were ovary in 10, digestive system in 21, breast in one.

Using a combination of CT findings may increase our ability to distinguish PC from DMPM.