[A case of radical resection for pancreatic head cancer with peritoneal dissemination treated with combination chemotherapy].

A 69-year-old man underwent surgery for pancreatic head cancer. During surgery, a few tubercles were found in the bursa omentalis, which were diagnosed pathologically as peritoneal dissemination. Curative resection was impossible, and exploratory laparotomy was completed. After surgery, 17 cycles of S-1/gemcitabine combination chemotherapy were administered for 1 year. Significant changes were not observed in the primary tumor on computed tomography (CT) scan, but the uptake of fluorodeoxyglucose (FDG) in the tumor decreased on positron emission tomography combined with CT(PET/CT), suggesting a decrease in tumor activity. Although imaging modalities could not identify distant or peritoneal metastases, levels of serological tumor markers increased at this time. Therefore, a second exploratory laparotomy was performed 13 months after the initial surgery. The nodules in the bursa omentalis had disappeared, and the patient underwent a pancreatoduodenectomy with common hepatic artery resection. Histopathological findings revealed mucinous carcinoma of the pancreas. The postoperative diagnosis was pT3, pN2, M0, Stage IVa.