Laparoscopic palliative tumor resection and peritoneal effusion drainage were performed, and postoperative pathology/immunohistochemistry (CK+, CR+, <b>CK5/6+, D2-40+, WT1+</b>, CD20-, CDX2-) confirmed epithelioid mesothelioma of the omentum. The gene discussed is WT1; the disease is malignant epithelioid mesothelioma.