Abstract: To investigate the diagnosis and treatment of the duodenal gastrointestinal stromal tumors (GISTs).
Methods:The clinical data of 14 patients with duodenal GISTs who were admitted to the Xinhua Hospital of the Shanghai Jiaotong University from January 2009 to December 2013 were retrospectively analyzed. The clinical presentation and results of imaging examination were analyzed. The surgical procedures were selected according to the location  and size of the tumor and tumor infiltration. Chemotherapy was applied according to the risks of the tumor after the operation. Patients were followed up via phone call or out patient examination every 3 months to learn the symptoms, and the prognosis of the patients was evaluated by body examination, blood biochemistry test, chest X ray examination. Patients were followed up till August 2014. The count data were analyzed using the chi square test, the survival rate was analyzed by Kaplan Meier method, and the survival was analyzed by Log rank test.
Results:The initial symptoms included melaena in 7 cases, discomfort in the  right hypochondriac region of the abdomen in 3 cases, painless mass in the right hypochondriac region of the abdomen in 2 cases, acute upper gastrointestinal hemorrhage in 1 case and jaundice in 1 case. All the 9 patients received B sonography, and the space occupying lesions were originated from the duodenum in 4 patients; 14 patients received computed tomography, and 9 patients had duodenal space occupying lesions; 12 received endoscopy and endoscopic ultrasonography, compressed changes or submucosal apophysis were detected in 11 cases; 11 patients received histopatholgical examination and 8 patients were confirmed as with stromal tumors by biopsy. Fourteen patients received radical resection, including pancreaticoduodenectomy in 7 cases and local resection in 7 cases (local resection+repair in 2 cases, duodenectomy in 4 cases and distal subtotal gastrectomy in 1 case). One patient was complicated with pancreatic fistula, 2 with gastroplegia and 3 with anastomotic fistula, and they were cured by non surgical treatment. The incidence of complications was 5/7 in patients who received pancreaticoduodenectomy, which was significantly higher than 1/7 in patients who received local resection (χ2 =4.667, P<0.05). The mean diameter of the tumor was 4.5 cm (range, 2.5 -10.0 cm). The diameters of the tumors of 10 patients were under 5.0 cm, and 4 were above 5.0 cm. No swelling lymph nodes were detected during the operation, and no lymph node metastasis was detected in intra and postoperative pathological examination. Duodenal GISTs were confirmed by pathological examination. The mitotic count was under 5/50 HPF in 9 patients, between 5/50 HPF and 10/50 HPF in 3 patients and above 10/50 HPF in 2 patients. The expression of CD34 was positive in 12 patients, the expression of CD117 was positive in 13 patients, and the expression of the smooth muscle actin was negative in 14 patients. Three of the 4 patients who were in the high risk phase were treated by imatinib, and the other 1 patient was not treated by imatinib due to economic reasons; 4 patients in the medium risk phase were treated by imatinib for 1 year; 3 of the 6 patients in the low risk phase were treated by imatinib for 1 year, and the other 3 patients did not receive adjuvant chemotherapy. All the 14 patients were followed up for 8 -65 months, and 3 patients died during the follow up. The survival rates of patients who received pancreatoduodenectomy and local resection were 72% and 84%, with significant difference (χ2 =1.238, P>0.05).
Conclusions:The clinical presentation of the duodenal GISTs is untypical. B sonography, abdominal computed tomography, endoscopy and endoscopic ultrasonography are effective for preoperative diagnosis. Surgical resection is the first choice for the treatment of duodenal GISTs. Adjuvant chemotherapy should be applied for patients in the medium or high risk phase or have potential metastasis of tumor. Imatinib is considered as the first choice of chemotherapeutics, however, if resistance exists, sunitinib or regorafenib could be an alternative option.