A case of malignant peritoneal mesothelioma suggesting the utility of combining double-contrast radiography and endoscopy with computed tomography for diagnosis.

A 68-year-old woman presented with abdominal pain, weight loss, and vomiting. Enhanced computed tomography (CT) showed slightly increased density in the mesentery and edema of the third portion of the duodenum and proximal jejunum. Little ascites, but no primary lesion, lymph node metastases, or distant metastases, were observed. Endoscopic findings included erythema and edema in the distal duodenum and proximal jejunum without epithelial lesions. Double-contrast radiography revealed transverse ridging with convergence, suggesting a serosal lesion. We suspected disease involving the serosa, such as mesenteric panniculitis. However, the lesion was definitively diagnosed as malignant peritoneal mesothelioma based on a biopsy specimen obtained at laparotomy. The combination of transverse ridging with convergence on double-contrast radiography and mucosal edema without epithelial lesions on endoscopy was consistent with a disorder involving the serosa. Transverse ridging with convergence is helpful to diagnose serosal pathology such as malignant peritoneal mesothelioma. Combining the findings of double-contrast radiography and endoscopy with computed tomography may facilitate diagnosis of malignant peritoneal mesothelioma. Thus, in case of increased density of mesentery and wall thickness on CT image with transverse ridging with convergence on double-contrast radiography and without epithelial lesion on endoscopy, malignant peritoneal mesothelioma must be considered.