There were malignant ascites and peritoneal nodules at laparoscopy which corresponded to infiltrative epithelioid mesothelioma, characterised by positive labelling for mesothelial-related markers calretinin, WT1, CK5.6, and CK7, whilst there was no labelling for carcinoma-related markers TTF1, BerEP4, and CDX2, as well as no labelling for CK20, CD138, neuroendocrine markers chromogranin, and synaptophysin. The gene discussed is CDX2; the disease is carcinoma.