Well-differentiated glands infiltrating through the ovarian stroma. Metastatic deposits may mimic primary ovarian tumors both clinically as well as morphologically. Features favoring metastases from colon include: bilateral involvement, surface involvement, infiltrative pattern of growth, signet ring cells, cribriform growth, dirty necrosis, vascular invasion, and lack of squamous metaplasia. Immunohistochemical profile of metastatic colonic adenocarcinomas: CK7-, CK20+, CEA+, CA-125-, MUC2+, CDX2+ and beta-catenin + (nuclear staining). See next image for features favoring primary ovarian tumor over metastases.