Metachronous primary colon and periampullary duodenal cancer: A case report

RATIONALE Primary periampullary duodenal cancer accounts for 3% to 17% of periampullary cancers. There are no previous reports of metachronous primary colon and periampullary duodenal cancer. PATIENT CONCERNS We present a case of primary periampullary duodenal cancer that occurred metachronously after colon cancer. DIAGNOSES Imaging and endoscopic examinations, serum tumor marker levels, and pathology confirmed metachronous colon and periampullary duodenal cancer, with 14-month interval between the diagnoses of the 2 malignancies. INTERVENTION The patient received right hemicolectomy combined with mFOLFOX6 chemotherapy for colon cancer and pancreatoduodenectomy for periampullary duodenal cancer. OUTCOMES The patient has been followed up for 6 years since the pancreatoduodenectomy and shows no signs of recurrence or metastasis. LESSONS The risk of developing a second malignancy may be associated with the site of the first tumor. Patients with right colon cancer may have particularly high risk of developing small intestinal cancer, including duodenal cancer. Early detection and active surgical treatments can improve prognosis. Long-term regular follow-up is necessary to detect new malignancies occurring after the diagnosis colon cancer.