En-bloc resection of a giant retroperitoneal lipoma: a case report and review of the literature

Background 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. Case presentation We present the case of a 73 year-old
Caucasian patient with a giant retroperitoneal lipoma of 9 kg
measuring 55 cm in diameter. The patient presented with abdominal
pain and swelling that had been slowly progressive for the last 15
years. On computerized tomography an immense retroperitoneal tumor
was revealed. Intraoperatively, the tumor did not show any signs of
infiltrative growth, therefore sole tumor extirpation was
performed. Conclusion Retroperitoneal lipomas are not clearly
distinguishable from well-differentiated liposarcomas on imaging
and even biopsies may be misleading. Moreover, abdominal symptoms,
i.e. pain, obstipation and dysphagia may occur due to mechanical
displacement. Therefore, surgical exploration with complete
oncological resection is the therapy of choice if malignity cannot
be ruled out.