Signet ring cell carcinoma of the appendix manifesting as colonic obstruction and ovarian tumors: report of a case.

Appendiceal cancer is rare and associated with a poor prognosis because it is usually found at an advanced stage. We report a case of appendiceal adenocarcinoma manifesting as a colonic obstruction with a lower abdominal mass. Laparotomy revealed bilateral ovarian tumors and a small appendiceal tumor with peritoneal metastases. We performed ileocecal resection, colectomy, and oophorectomy, following which a histological diagnosis of signet ring cell carcinoma was made. Immunohistochemical analysis revealed positive expression of cytokeratin 7 and 20, and mucin core protein 2 (MUC2), compatible with appendiceal cancer and Kruckenberg metastases. When a patient is found to have disseminated pelvic signet ring cell carcinoma of unknown origin, the appendix should be considered as a possible primary site.