A 60-year-old man underwent palliative surgery with a diagnosis of unresectable cancer, and he visited our hospital for further treatment. Since the cancer was unresectable and multiple hepatic tumors were revealed in CT images that were not metastases, we decided to perform curative surgery for the pancreatic cancer accompanied by partial liver invasion. Pancreaticoduodenectomy plus partial hepatectomy were performed, and 2 tumors were detected in the resected specimen: one in the pancreas-duodenum region and a submucosal tumor in the duodenum bulb. The large tumor that occupied the pancreasduodenum region was histologically diagnosed as an undifferentiated carcinoma, and the duodenal submucosal tumor was consistent with findings of a poorly differentiated adenocarcinoma. Two years after surgery, CT examination revealed a mass extending into the inferior vena cava(IVC)from near the right renal vein. We eventually diagnosed lymph node recurrence with tumor thrombosis inthe IVC and started chemotherapy(FOLFIRINOX). After the tumor decreased, we performed salvage surgery involving resection of the lymph node, thrombectomy, and right nephrectomy. The tumor revealed atypical cells in the region of thrombosis, and the pathological findings were not in conflict with the findings of metastases from pancreatic cancer 2 years prior. After the treatment, chemotherapy was administered and he survived without any recurrence for 15 months after surgery.