Is MDCT an accurate tool to differentiate between benign and malignant etiology in diffuse peritoneal disease?

There is often considerable overlap of imaging findings in benign and malignant peritoneal diseases. We evaluated patients with diffuse peritoneal disease, to assess the diagnostic value of MDCT in predicting benign or malignant etiology in patients with unknown etiology, by analyzing the various patterns of involvement, particularly tuberculosis (TB) vs malignancy.

One hundred and thirty-six patients with diffuse peritoneal disease who had abdominal CT and subsequently underwent omental biopsies were included in the study. Peritoneal, mesenteric and omental involvement by disease was evaluated on CT using specific parameters. The presence of lymphadenopathy, ascites, scalloping of organs, involvement of liver and spleen, were also compared between benign and malignant conditions using histopathology as the gold standard.

In 136 patients, 72 benign and 64 malignant pathologies were classified as per histopathology. Higher age (p < 0.001), increasing omental thickness (mean 25.2 mm, p = 0.004), omental caking (p < 0.001), > 10 mm mesenteric/peritoneal nodules (p < 0.03), visceral scalloping (p = 0.001), free ascites (p = 0.003), serosal involvement (p = 0.004) and bilateral pleural effusion (p = 0.02) were associated with malignant etiology. Mesenteric thickening/stranding (p = 0.02), mesenteric adenopathy (p < 0.001), necrotic nodes (p = 0.02), splenomegaly (p =  < 0.001) and higher attenuation (> 20HU) of ascitic fluid (p < 0.001) were associated with benign etiology. The presence of mesenteric thickening or stranding (p = 0.01), splenomegaly (p = 0.02), higher ascitic fluid attenuation > 20HU (p =  < 0.01), mesenteric adenopathy (p < 0.01), necrotic nodes (p = 0.03) favored tuberculosis. CT had diagnostic accuracy (79.3, 86.7%), sensitivity (79.2, 74.6%) and specificity (79.4, 97%) for observers 1 and 2, respectively (Kappa 0.713).

Contrast-enhanced MDCT has good sensitivity, specificity and accuracy in differentiating benign and malignant etiologies of diffuse peritoneal disease. Multiple common parameters can be used to differentiate between tuberculous peritonitis and peritoneal carcinomatosis.