Case of peritoneal dissemination of colon cancer in which PET/CT was useful in determining the indicated surgical procedure.

The right half of the colon was resected in a 70-year-old woman in August 2002 for ascending colon cancer. The peritoneum was also resected because of metastasis (Stage IV). Since tumor markers gradually increased, positron emission tomography (PET)/ computed tomography (CT) revealed peritoneal dissemination. Abdominal pain appeared 40 months after surgery. Barium enema findings revealed an ileal constriction approximately 25 cm from the anastomosed site toward the anus. Repeat PET/CT revealed peritoneal dissemination coinciding with ileal constriction. CT did not reveal well-defined tumor shadows. The patient was diagnosed with constriction associated with peritoneal metastasis and underwent surgery. Surgical findings revealed a roughly 2-cm peritoneal metastatic focus and ileal constriction. The site was resected and anastomosed. Postoperative progress was favorable; the patient was discharged and enjoys a favorable quality of life through outpatient adjuvant chemotherapy. PET/CT is suggested to be useful in observing the progress of peritoneal dissemination and may be of assistance in determining the course of treatment.