Aggressive undifferentiated pleomorphic sarcoma of the stomach involving long-term survival: A case report and literature review.

Primary gastric undifferentiated pleomorphic sarcoma (UPS) is a rare disease with insufficient long-term follow-up data. In the present study, a 70-year-old male complained of abdominal fullness and visited our hospital. Abdominal computed tomography revealed a large tumor in the upper part of the stomach, which was accompanied by smaller tumors in the small intestinal mesentery. An endoscopic ultrasound-guided fine-needle biopsy examination of the gastric tumor revealed features of pleomorphic sarcoma and high-grade spindle-shaped cells. Total gastrectomy was performed on the primary tumor, together with combined resection of the small intestine for the metastatic tumors. However, the tumor recurred in the mesentery of the sigmoid colon 6 months after the operation. A second operation was performed to resect the recurrent tumor. Since the second surgical procedure, the patient has remained free from recurrence for >7 years. Although the prognosis of abdominal UPS was considered to be poor, even after curative surgery, the present case experienced a long-term survival of gastric UPS after undergoing surgical resection alone.