Nine patients had clinical symptoms (anorexia, n = 4; abdominal distension, n = 3; nausea, n = 2), 10 had elevated tumor marker levels (carcinoembryonic antigen [CEA], n = 4; carbohydrate antigen (CA) 19–9, n = 5; CA125, n = 3), and 14 had suspicious findings suggestive of PM on axial CT images (thickening of the intestinal wall, n = 11; ascites, n = 4; intraperitoneal nodules, n = 0; thickening of the intestinal mesentery, n = 1). Here, CEACAM5 is linked to neoplasm.