A huge pancreatic lipoma mimicking a well-differentiated liposarcoma: A case report and systematic literature review.

Background: Pancreatic lipomas are thought to be very rare. Lipomas are usually easy to identify on imaging, particularly computed tomography (CT). But sometimes it's quite difficult to distinguish a lipoma from a well-liposarcoma without histologic result.

Case Summary: Here, we present a case of pancreatic lipoma in a 59-year-old female. She was asymptomatic and had no medical history of note. CT and magnetic resonance imaging revealed a mass like well-differentiated liposarcoma in the pancreatic head, positron emission tomography/CT showed a low fluorodeoxyglucose uptake and laboratory tests revealed elevated transaminase and carbohydrate antigen-199 levels. Finally, the patient underwent a pancreaticoduodenectomy. Histologically, mature adipocytes were noted in the bulk of the tumor. Accordingly, the pathologic diagnosis of the pancreatic neoplasm was lipoma. To our knowledge, this case is the first example of a suspected well-differentiated liposarcoma that was actually a pancreatic lipoma. We also highlight the radiological features distinguishing a pancreatic lipoma from a pancreatic liposarcoma and briefly review the literature.

Conclusion: Pancreatic lipomas show no obvious gender bias and most commonly occur in the head of the pancreas, of which the maximum diameters are often less than 5 cm, and small, asymptomatic non-compressed lipomas require follow-up only. Surgical excision should be considered when the tumor has compressed important tissues or is difficult to distinguish from a liposarcoma, the choice of surgery depends on the intraoperative presentation.