Synchronous Pancreatic Acinar Cell Adenocarcinoma and Gastric Adenocarcinoma: a Case Report and Literature Review

Background: Multiple primary malignant tumors are two or more malignancies in an individual without any relationship between the neoplasms. In recent years, increasing number of cases have been reported. However, Synchronous double primary gastric cancer and pancreatic acinar cell carcinoma are relatively rare to be reported. Further, most pancreatic tumors are consistent with pancreatic ductal adenocarcinomas, and other histologies are rare. We present the first case of synchronous pancreatic acinar cell adenocarcinoma and gastric adenocarcinoma.Case presentation: A 69-year-old man came to our department with a history of vomiting, epigastric pain, and weight loss. Imaging revealed space-occupying lesions in the stomach and the tail of the pancreas, respectively. The patient underwent laparoscopic radical gastrectomy and pancreatectomy simultaneously. The pathologies of surgical specimens were completely different: the resected gastric specimen was a moderate to poorly differentiated adenocarcinoma, whereas the pancreatic tumor was consistent with acinar cell carcinoma. The patient was treated with six cycles of oxaliplatin and S-1 chemotherapy. As of March 2021, the patient was healthy without any recurrence or metastasis. After reviewing lots of literatures on simultaneous pancreatic and gastric cancers at home and abroad, we discuss the clinical characteristics of these rare synchronous double cancers. Most of the cases had undergone surgery and adjuvant chemotherapy, and all of the cases were pathologically confirmed by postoperative specimen. Conclusions: Synchronous pancreatic acinar cell and gastric adenocarcinoma can occur and should be considered when tumors are found in these organs.