Background and Aims: Undifferentiated pleomorphic sarcoma (UPS), previously known as malignant fibrous histiocytoma (MFH), is a malignant tumor of mesenchymal origin, accounting for more than 20% of all soft tissue sarcomas, most of which occur in the limbs, body trunk and retroperitoneal space. The occurrence of UPS in the pancreas is extremely rare. Although there are some reports at home and abroad, most of them are presented as individual case report, and the data analysis of larger series of patients are scarce. This article was written to discuss the clinical characteristics, diagnosis and treatment as well as the prognosis of this condition through analyzing one patient case of pancreatic UPS treated by the author’s team combined with the literature data. 
Methods: The clinical data of one patient with pancreatic UPS diagnosed and treated in the Department of Hepatobiliary Surgery of the Affiliated Hospital of Inner Mongolia Medical University was retrospectively analyzed. Meanwhile, a search of the relevant literature from the national and international databases was performed. Then, a pooled analysis of the same medical cases was conducted. 
Results: There a total of 32 patients (including our case and 31 cases reported in the literature) were enrolled in the study. Of the patients, 20 cases were males and 12 case were females, with a median age of 54.6 (22–74) years. The pathological types were classified as giant cell tumor in 9 cases, myxoid tumor in 5 cases, and pleomorphic tumor in 18 cases. The tumors were located in the head of the pancreas in 13 cases, in the body and tail of the pancreas in 12 cases, in the body of the pancreas in 3 cases, in the tail of the pancreas in 2 cases and in whole pancreas in 2 cases. Preoperative diagnosis was pancreatic cancer in 8 cases of, pancreatic tumor and space occupying lesion in 6 cases, pseudocyst in 4 cases, cystadenoma in 4 cases, pancreatic tumor in 3 cases of, and interstitial tumor, fibrosarcoma, inflammatory lesion in one case each and unavailable in 4 cases. The clinical manifestations included rapidly progressive enlargement of soft tissue lump, frequently accompanied with pressure symptoms or nausea and vomiting, epigastric discomfort, abdominal distension, weight loss or jaundice. The correct diagnosis was made in none of the patients. All the 32 patients underwent surgical treatment, perioperative death occurred in one case, and the overall survival time is 15.3 months. 
Conclusion: The pancreatic UPS is a highly malignant tumor with no specific clinical manifestations, high likelihood of metastasis and recurrence, and dismal prognosis. Early and complete resection of the tumor to obtain R0 resection is essential for surgical treatment. However, even if extensive resection or radical resection is performed in some cases, local tumor recurrence or distant metastasis still cannot be avoided, due to the special biohistological characteristics of pancreatic UPS. Postoperative radiotherapy and chemotherapy may probably improve survival of the patients.