ABSTRACT
The concern about multiple primary cancers has been raised in recent years, but their cause has yet to be elucidated clearly. It has been speculated that many factors may contribute, such as family history, genetic factors, chemotherapy, and radiotherapy.(1) The incidence of multiple primary cancers is estimated to be 13%. However, synchronous multiple primary cancers of the stomach and duodenum are uncommon due to the rarity of duodenal cancer. Duodenal cancer poses diagnostic difficulties because of its rarity, non- specific signs and symptoms, and the fact that duodenum is usually ignored during upper gastrointestinal endoscopy. This 71-year-old female patient was diagnosed with double primary cancer of the stomach and duodenum, which was found by abdominal computed tomography preoperatively, and she underwent a Whipple procedure. The histological diagnosis revealed poorly-differentiated adenocarcinoma in the stomach and moderately-differentiated adenocarcinoma in the duodenum. Here we report a case of synchronous double primary cancer of the stomach and duodenum with a review of the literature.