[74] Giant retroperitoneal lipoma: A case report and review of the literature

Objective: To report on a very rare case of giant retroperitoneal lipoma and a literature review. Retroperitoneal lipomas are an extremely rare condition with only 17 cases described in the literature since 1980. They can reach enormous size and cause significant abdominal symptoms. The most important differential diagnosis is the well-differentiated liposarcoma, which preoperatively often may not definitely be ruled out. Methods: We present the case of a 72-year-old woman with a giant retroperitoneal lipoma. The patient presented with abdominal pain and the appearance of a gradually increasing abdominal mass. The radiological explorations found a voluminous mass of retroperitoneal fatty density having a relationship with the psoas muscle of 17 × 21 cm causing deviation of the intestinal structures. Results: Exploratory laparotomy was indicated with the aim of en bloc total tumour resection for potential malignancy. Intraoperatively demarcated, there were two well-limited and encapsulated masses, the first mass weighed 665 g and measured 18 cm, the second weighed 1750 g and measured 24 cm. The operative follow-up was without incident. Conclusion: Retroperitoneal lipomas are not clearly distinguishable from well-differentiated liposarcomas on imaging and even biopsies may be misleading. Moreover, abdominal symptoms, e.g. pain, constipation and dysphagia, may occur due to mechanical displacement. Therefore, surgical exploration with complete oncological resection is the therapy of choice if malignancy cannot be ruled out