Partial resection of the second portion of the duodenum for gastrointestinal stromal tumor after effective transarterial embolization.

We report herein the case of 64-year-old man with gastrointestinal stromal tumor (GIST), who was treated by partial resection of the duodenum after preoperative transarterial embolization. He presented to our hospital with a history of tarry stools, dizziness, and severe anemia (hemoglobin, 7.5 g/dl). Gastroduodenal endoscopy revealed the presence of a submucosal tumor in the second portion of the duodenum. The presence of the tumor was subsequently confirmed by double-contrast gastrointestinal radiography and abdominal computed tomography. Super-selective angiography showed tumor staining fed from the anterior and posterior superior pancreaticoduodenal arteries, and the inferior pancreaticoduodenal artery. Two weeks after transarterial embolization through these vessels, the tumor size was found to have shrunk to 40% of its original size. Partial resection of the duodenum was performed and absence of tumor cells at the surgical margin was confirmed by intraoperative frozen-section examination. Histopathological examination revealed that the duodenal submucosal tumor consisted of spindle cells, and immunohistochemical analysis revealed positive tumor staining for c-kit protein, CD34 and alpha-smooth muscle actin (SMA), and negative staining for desmin and S-100; the positivity rate for MIB-1 staining was 2.2%. Based on these findings, the tumor was diagnosed as a GIST of low-grade malignancy, classified as the muscular type. It is considered that preoperative treatment of duodenal GISTs, such as transarterial embolization, may be useful for reducing the extent of resection, from pancreaticoduodenenctomy to a partial resection.