Dedifferentiated Liposarcoma Mimicking a Primary Colon Mass

Int J Surg Pathol. 2018 Apr;26(2):174-179. doi: 10.1177/1066896917731517. Epub 2017 Sep 26.


Dedifferentiated liposarcoma is typically a nonlipogenic high-grade sarcoma that arises from well-differentiated liposarcoma. It most commonly presents as a large mass in the retroperitoneum. Significant involvement of the gastrointestinal tract by dedifferentiated liposarcoma is uncommon. We present a unique case of dedifferentiated liposarcoma radiographically mimicking a primary colon mass with resulting intussusception; stranding of the adjacent adipose tissue was presumed to be a secondary reactive change. On histopathologic analysis of the hemicolectomy specimen, a high-grade sarcoma was seen growing through the colonic wall, and the majority of the surrounding pericolonic adipose tissue was actually composed of well-differentiated liposarcoma with characteristic fibrous bands rather than benign fat with reactive fibrosis. This case raises awareness that well-differentiated liposarcoma and dedifferentiated liposarcoma can rarely present as a primary intestinal mass mimicking colon cancer or other more common entities. When radiographic examination shows a perigastrointestinal or retroperitoneal fatty mass and/or stranding of the fat adjacent to a solid gastrointestinal mass, this unusual scenario should be considered in the radiologic differential diagnosis. Pathologists should keep dedifferentiated liposarcoma in the initial histologic differential diagnosis for any high-grade spindle cell tumor of the retroperitoneum or intra-abdominal visceral organs.

Keywords: MDM2; colon cancer; liposarcoma; retroperitoneum; sarcoma.

Publication types

  • Case Reports

MeSH terms

  • Colonic Neoplasms / diagnosis*
  • Colonic Neoplasms / pathology
  • Diagnosis, Differential
  • Humans
  • Liposarcoma / diagnosis*
  • Liposarcoma / pathology
  • Male
  • Middle Aged
  • Retroperitoneal Neoplasms / diagnosis
  • Retroperitoneal Neoplasms / pathology