Ultrasound-guided percutaneous biopsy of an abdominal wall lesion was executed and histopathological examination identified localization of pseudomyxoma peritonei, with immunohistochemical staining being positive for cytokeratin 20 (CK-20) and CDX-2 and negative for cytokeratin 7 (CK-7). The gene discussed is KRT20; the disease is pseudomyxoma peritonei.