The patient was a 78-year-old woman who underwent surgery for cecal carcinoma perforation and peritonitis (ileocecal resection and ileostomy)in January 2012. Liver metastasis was observed on the postoperative computed tomography (CT) scan and chemotherapy was performed. However, in October, a CT scan revealed a tumor, 9 cm in diameter, in the right ovary. Based on the results of a positron emission tomography (PET)-CT scan, this was suspected to be primary or metastatic ovarian cancer, and bilateral salpingo-oophorectomy was performed the following January. Histopathology and immunostaining indicated that this was a cytokeratin (CK) 20-positive and CK7-negative adenocarcinoma, and the patient was diagnosed with metastatic cecal carcinoma.