LAUSR

Undifferentiated pleomorphic sarcoma (UPS), which was previously known as malignant fibrous histiocytoma (MFH), was first described in 1961 by Kauffman as a histiocytic tumor with storiform growth in children [1]. On the new 2013 WHO classification of soft-tissue tumors, a new class of Bundifferentiated/unclassified sarcoma^ was created, with the deletion of MFH replaced by UPS and attributed to this category. UPS is a type of malignant sarcoma that occurs most frequently in patients aged between 50 and 70 years [2], accounting for 28% of all soft-tissue sarcomas [3]. The major locations for UPS are the lower (49%) and upper extremities (19%), while tumors of the retroperitoneum and abdominal cavity account for 16%, and those of trunk account for 9% of the cases [4]. The histological morphology varies, but the classic form is composed of spindle-shaped and round cells. The prognosis for UPS is very poor because of its strong chances of regional invasiveness and distant metastasis. We report a rare case of recurrent intraperitoneal UPS. The patient was brought to our department because of locally recurrent intra-abdominal UPS 1 year after the operation. He underwent en-bloc resection of the tumor along with left hemicolectomy in our department. However, only 1 month after he was discharged from our hospital, we were deeply shocked that the tumor recurred and was larger than before. Case Report