Abstract
This is a case of a 71-year-old man who had multiple synchronous retroperitoneal liposarcoma (LPS) foci composed of both well-differentiated and dedifferentiated histologies. In addressing this, the patient underwent a margin negative resection of a 11.8×8.8 cm right-sided dedifferentiated LPS requiring pancreaticoduodenectomy; however, a 13.1×7.2 cm left-sided well-differentiated LPS (WDLPS) was not resected due to its involvement of the proximal mesenteric vessels. The patient's postoperative course was complicated by grade B postoperative pancreatic fistula involving the anatomical territory of the residual WDLPS. Over the next 12 months, serial CT scans demonstrated a stepwise reduction in size of the WDLPS until it completely regressed. The authors hypothesise that enzymes shed from the pancreatic fistula initiated the autodigestion and subsequent necrosis of the WDLPS with associated tumour regression. © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.