CT DIFFERENTIATION OF TUBERCULOUS PERITONITIS AND PERITONEAL CARCINOMATOSIS

OBJECTIVE. The purpose of this study was to determine the potential of CT for distinguishing tuberculous peritonitis from peritoneal carcino matosis in 135 clinically or pathologically proven cases. MATERIALS AN D METHODS. Abdominal CT scans in 135 patients of tuberculous peritonit is (n = 42) and peritoneal carcinomatosis (n = 93) with documented ome ntal, mesenteric, or peritoneal pathology were retrospectively reviewe d. CT findings were evaluated in each group of patients for the morpho logic appearance of mesenteric or omental abnormalities as well as for visualization of the spleen and liver, the lymph nodes, and ascites. Statistical comparisons using multivariate logistic regression analysi s were performed to adjust for the differences in CT findings between the two groups. RESULTS. Mesenteric changes were more commonly seen in patients with tuberculous peritonitis (98%) than in patients with per itoneal carcinomatosis (70%) (p < .01). Micronodules (less than 5 mm i n diameter) were noted in approximately one half of patients with tube rculous peritonitis or peritoneal carcinomatosis, but macronodules (gr eater than or equal to 5 mm in diameter) were much more frequently see n in patients with tuberculous peritonitis (52%) than in patients with peritoneal carcinomatosis (12%) (p < .01). The omentum appeared to be more irregularly infiltrated in peritoneal carcinomatosis patients (p < .01). The thin omental line covering the infiltrated omentum was se en in 13 patients with tuberculous peritonitis but in only four patien ts with peritoneal carcinomatosis (p < .01). In peritoneal or extraper itoneal masses in patients with tuberculous peritonitis, a low-density center was seen in 18 cases (43%) and calcification was noted in six cases (14%). The prevalences of splenomegaly and splenic calcification were higher in patients with tuberculous peritonitis. Using multivari ate analysis, we calculated the sensitivity of CT for predicting tuber culous peritonitis and peritoneal carcinomatosis as 69% and 91%, respe ctively. CONCLUSION. Although most CT findings that we analyzed overla p these diseases, using a combination of CT findings increased our abi lity to distinguish tuberculous peritonitis from peritoneal carcinomat osis.