Jejunal Undifferentiated Spindle Cell Sarcoma with Intussusception Revealed by ¹⁸F-FDG PET/CT

Spindle cell sarcoma is a malignant tumor with low incidence. They can occur in the soft tissue, bone, or viscera. The characteristics of morphology, density, and metabolism of spindle cell sarcoma are related to the location of the lesion. A 61-year-old woman presented with vomiting after eating for 2 weeks. Signs of peritoneal irritation were involved, but no response for symptomatic treatment included antiemetic and antispasmodic therapy. Abdominal computed tomography (CT) indicated a mass in the intestinal tract in the pelvic cavity. Then, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/CT was performed, which interestingly detected a jejunal malignancy mass in the left upper abdomen with annular high uptake of ¹⁸F-FDG, which was complicated by intussusception and intestinal obstruction. Finally, the jejunal mass was pathologically clarified as an undifferentiated spindle cell sarcoma.