Primary Dedifferentiated Liposarcoma of the Duodenum: A Report of a Rare Case With a Review of the Literature.

Primary and metastatic tumors of the duodenum are rare, and primary duodenal dedifferentiated liposarcomas (DDLPS) of this region are exceptionally uncommon. DDLPS is an aggressive malignancy characterized by a high risk of recurrence and metastasis. This report describes the case of a 43-year-old woman who presented with a 20-day history of isolated abdominal pain. CT images demonstrated a 68 x 120 mm lesion involving the distal portions of the duodenum. Intraoperatively, the lesion was found to be confined to the third and fourth portions, and a segmental duodenal resection with duodenojejunostomy using a circular stapler was performed. During the postoperative period, the patient experienced transient cholestatic findings likely secondary to papillary obstruction. After clinical improvement, she was lost to follow-up for seven months during doxorubicin therapy and later re-presented with extensive metastatic disease, ultimately resulting in death. Given the extremely limited number of similar cases, no standardized treatment strategy exists. This case highlights the importance of considering DDLPS in the differential diagnosis of duodenal masses, even in patients presenting with nonspecific symptoms, and provides additional insight that may guide clinical decision-making in future cases.