[A Case of Retroperitoneal Dedifferentiation Type Liposarcoma in Which Total Pancreatectomy and Radiation Therapy Was Performed at the Remnant Pancreas after Pancreaticoduodenectomy].

A 75-year-old man presented with a fever. Computed tomography revealed a 10 cm solid tumor under the duodenum. A pre-operative diagnosis of liposarcoma was established using biopsy. Pancreaticoduodenectomy was performed, and the pathological examination led to the diagnosis of dedifferentiation type liposarcoma. Two years later, the liposarcoma recurred at the remnant pancreas. A total remnant pancreatectomy was performed. The pathological examination revealed dedifferentiated type liposarcoma and positive surgical margins. Therefore, radiotherapy of 59.4 Gy in 33 fractions was performed at the recurrence area. The patient has been recurrence-free from 1 year 6 months since the second operation.