CT differentiation of malignant peritoneal mesothelioma and tuberculous peritonitis

The aim of this study was to determine which computed tomography (CT) findings were useful in differentiating malignant peritoneal mesothelioma (MPM) and tuberculous peritonitis (TBP).

CT scans performed in 53 patients with MPM and 27 patients with TBP confirmed by pathology were retrospectively reviewed. The CT findings were evaluated for the morphologic appearance of ascites, peritoneum, mesenterium and omentum involvement, enlarged lymph nodes, solid abdominal viscera infiltration and metastases, and thoracic changes. The Pearson χ (2) test was used to compare differences between groups.

Patients in both groups displayed a high proportion of peritoneum and mesenterium thickening. However, there were no obvious differences observed for ascites or swollen lymph nodes. There were significant differences in the following aspects between the two groups: (1) smooth peritoneal thickening was more frequent in patients with TBP, while irregular thickening was more frequently observed in patients with MPM; (2) caked omentum stratification was more common in patients with MPM; (3) mesentery involvement was less commonly observed in patients with TBP; (4) abdominal viscera infiltration and pleural plaques were more common in patients with MPM (46/53 and 48/53, respectively) than in those with TBP (0/27 and 0/27); and (5) more patients in the TBP group (14/27) displayed pleural effusion, and extraperitoneal tuberculosis was more common in patients with TBP (20/27).

Although most CT findings analyzed are observed in both diseases, each disease has its own several unique characteristics. Therefore, using a combination of CT findings may increase our ability to distinguish TBP from MPM.