Complete wedge resection for duodenal gastrointestinal stromal tumour: A case series of three patients

Introduction Duodenal gastrointestinal stromal tumours (GIST) are rare. Therefore, difficulties are experienced when selecting the appropriate surgical procedure in patients with duodenal GISTs. This report presents the cases of three patients with duodenal GISTs who underwent wedge resection. This report would help surgeons identify clinical features and surgical procedures in patients with duodenal GISTs. Presentation of case Three patients were diagnosed with duodenal submucosal tumours. The first patient presented with melena, the second with postoperative anaemia, and the third with an incidental finding of a large abdominal tumour after presenting with ischaemic colitis. All tumours arose in the 2nd portion of the duodenum and measured 3.5, 3, and 9.2 cm, respectively. Wedge resection of the duodenum was performed in all patients. In patients one and two, simple closure of duodenal wall was performed after wedge resection. In patient three, side-to-side anastomosis with the jejunum was performed because a large area of the wall was removed using the wedge resection technique. Pancreatoduodenectomy was avoided in all patients. Recurrence was not noted in any patient. Discussion Since GISTs are not generally associated with lymph node metastasis, local resection with negative margins is sufficient to surgically manage patients with GISTs. Conclusion Our results indicated the effectiveness of performing wedge resection for duodenal GISTs not in close proximity to the ampulla of Vater. Moreover, less invasive procedures should be adopted in patients with duodenal GISTs.

Herein, we report the cases of three patients with GISTs in the 2nd portion of the duodenum who underwent wedge resection. Pancreatoduodenectomy was avoided in all patients. Although wedge resection of the duodenum for GISTs has been selected as the common procedure, difficulties are often encountered in selecting appropriate All patients were treated by a senior associate professor. The operation was performed under general anaesthesia with all three patients in the supine position. Anastomosis or closure of the duodenum was performed by a hand-sewn technique using absorbent silk threads.
We performed a clinical 5-year follow-up using computed tomography (CT) scanning in all patients at our hospital.

Case report 1
An 84-year-old man sought consultation due to fatigue. Upon clinical examination, the physician found melena. Further blood test result revealed severe anaemia. Hence, he was referred to our hospital. On the same day, he was admitted to our hospital as an emergency case due to gastrointestinal bleeding. The patient had hypertension and received medications. Physical and laboratory examinations are shown in Table 1. Abdominal examination revealed no palpable masses. He was transfused with eight units of red blood cell. An emergency upper gastrointestinal endoscopy was performed, which revealed a 3-cm submucosal tumour located in the 2nd portion of the duodenum (Fig. 1A). Active bleeding was observed from the apex of the tumour. A haemostatic forceps was used to attempt bleeding termination, which was unsuccessful. On the 2nd and 3rd day of admission, repeat endoscopy and haemostatic therapy with transfusion of red blood cells and platelets were performed. The imaging findings are described in Figs. 1B and C. On admission day four, he presented with melena amounting to approximately 300 ml. Endoscopy was insufficient to stop the bleeding, which necessitated emergency surgery. On laparotomy, a 3-cm-sized duodenal submucosal tumour (SMT) was observed in the 2nd portion of the duodenum. No inferior vena cava (IVC) or pancreatic infiltration was observed ( Fig. 2A). Wedge resection of the duodenum was performed ( Fig. 2B). No postoperative complications were observed. On postoperative day 14, he was discharged.
Macroscopic examination demonstrated that the duodenal tumour appeared as a 35-mm SMT with an ulcer (Fig. 2C). Histopathological examination revealed spindle cell tumour. The tumour showed five Abbreviations: Hb, haemoglobin; Plt, platelets; RBC, red blood cell; WBC, white blood cell.  mitosis/50 high-power fields (HPFs). Immunohistochemical staining showed that the tumour cells were positive for c-KIT and CD34. He was diagnosed with duodenal GIST. According to Fletcher's risk classification, he was classified as having low-risk GIST. Five years postoperatively, no recurrence was reported.

Case report 2
A 58-year-old man underwent right inguinal hernia repair at our hospital. However, he developed postoperative anaemia. The patient had a tachyarrhythmia and received medications. Physical and laboratory examinations are shown in Table 1. No mass was palpated. The imaging findings are described in Figs. 3A and B. Endoscopic ultrasoundguided fine-needle aspiration failed to visualise the tumour.
He was hospitalised for elective surgery for SMT. Intraoperatively, a 3-cm extrinsic tumour was observed in the 2nd portion of the duodenum (Fig. 3C, D). No invasion into the adjacent organs was observed. Therefore, wedge resection of the duodenum was performed. No postoperative complications were observed. On postoperative day 19, he was discharged.
Macroscopic examination demonstrated that the 40-mm duodenal tumour resembled an SMT. Histopathological examination revealed spindle cells that had five mitosis/50 HPF and, immunohistochemically, were stained positive for c-KIT and CD34. Consequently, the patient was diagnosed with duodenal GIST. According to Fletcher's risk classification, he was classified as having low-risk GIST. Five years postoperatively, no recurrence was reported.

Case report 3
A 57-year-old woman presented with ischaemic colitis. During consultation, the patient underwent abdominal CT, which incidentally identified a 6-cm-sized retroperitoneal tumour. She declined tumour resection due to diabetes. However, tumour size increased throughout the year. Therefore, she was referred to our department for tumour resection. The patient had a history of myoma uteri.
Physical and laboratory examinations are shown in Table 1. Abdominal examination revealed a 10-cm palpable mass in the right upper quadrant of the abdomen. The imaging findings are described in Fig. 4A and B. We considered that the tumour was retroperitoneal in origin.
Intraoperatively, a 10-cm-sized giant tumour was located adjacent to the inferior duodenal flexure (Fig. 4C). The tumour was thought to originate from the duodenum as an SMT. IVC or pancreatic infiltration was not observed. Wedge resection of the duodenum was possible, despite the large size of the tumour. However, simple closure of duodenal wall was not possible due to the broad range of the wall. Therefore, a side-to-side anastomosis with the jejunum was performed. No postoperative complications were observed. On postoperative day 21, she was discharged.
The macro-and microscopic findings are shown in Figs. 4 and 5, respectively. Consequently, she was diagnosed with duodenal GIST (Fig. 5). According to Fletcher's risk classification, she was classified as having high-risk GIST, which necessitated adjuvant imatinib at a dose of 400 mg/day orally. Three years postoperatively, she experienced no

Discussion
Herein, three patients with GISTs in the 2nd portion of the duodenum underwent wedge resection. Pancreatoduodenectomy was avoided in all patients. Recurrence was not noted in any patient. This report would help all clinicians identify clinical features and treatments of duodenal GISTs.
Previous reports have summarised the clinicopathological features of duodenal GISTs [5,6], which most frequently occur in the 2nd, followed by the 3rd portion of the duodenum. All patients in our report presented with GIST in the 2nd portion of the duodenum, which is adjacent to the 3rd portion.
GIST commonly manifests most commonly with bleeding, followed by epigastric pain, jaundice, and bowel obstruction [7]. Compared with gastric GISTs, duodenal GISTs have higher incidence of bleeding [7]. Herein, the first patient presented with bleeding, which necessitated haemostatic therapy providing temporary bleeding relief. Upon recurrence, emergency laparotomy and wedge resection were performed because endoscopic haemostasis was unsuccessful.
Regarding the surgical procedure, local resection with negative margins is sufficient because GISTs are not associated with lymph node metastasis [8]. However, pancreatoduodenectomy or pyloruspreserving pancreatoduodenectomy for tumours close to the ampulla of Vater is required [3]. In contrast, segmental duodenectomy should be performed on large-sized tumours that do not preserve duodenal wall during local resection. This study suggested that local resection was sufficient for managing patients with duodenal GISTs without recurrence. Lee et al. indicated that limited resection including wedge resection of the duodenum was performed in 62% of 118 patients with duodenal GISTs [5]. They also suggested that limited resection was feasible and effective procedure in patients with especially small-sized and antimesenteric-sided duodenal GISTs regarding complications.
The Japanese clinical practice guidelines for GIST recommend resection of tumours measuring 2.5 cm because it is easy to perform [9]. However, the guidelines do not recommend laparoscopic resection of malignant GISTs. However, the minimally invasive nature of laparoscopic resection has led to its increased use for gastric GISTs [10]. A recent study that evaluated long-term outcomes of laparoscopic resection has found that it was feasible to perform in GISTs measuring >5 cm [11]. In 2008, Hiki et al. developed the laparoscopy endoscopy cooperative surgery (LECS), a minimally invasive surgery, for management of gastric SMTs and GISTs [12]. Recently, the LECS procedure successfully and safely managed patients with duodenal tumours measuring <2 cm [13]. Laparoscopic wedge resection or LECS are potentially feasible and safe surgical procedures for duodenal GISTs. However, it is more important to consider the type of oncological resection to be performed compared with the type of minimally invasive surgery. Therefore, neoadjuvant chemotherapy may be helpful for large tumours or tumours suspected of invading adjacent organs. Specifically, neoadjuvant imatinib treatment can decrease tumour size and prevent extensive resection and tumour rupture [14]. Huang et al. found that tumours in the 3rd portion of the duodenum were larger and had more severe surgical complications compared with other portions of the duodenum in patients with resected GIST from the duodenum and proximal jejunum [15]. Pathological diagnosis of GIST is required when administering neoadjuvant chemotherapy for large GISTs. Endoscopic ultrasonography (EUS) and EUS-guided biopsy are helpful in diagnosing GIST and evaluating neoadjuvant therapy [16]. Herein, EUS was not performed in patient one due to bleeding. However, EUS and EUS-guided-fine-needle aspiration were attempted in patients two and three. However, it was Regarding recurrence risk stratification, Fletcher et al. [17], Miettinen and Lasota [18], and Joensuu et al. [19] classifications are generally used. Fletcher's risk stratification is a well-established method for recurrence risk classification. Miettinen et al. established risk stratification by adding the site of organ affected by the tumour, to its size and mitosis count [18]. In addition, the risk stratification method of Joensuu et al. added tumour rupture as a variable [19]. Compared with GISTs in other organs, duodenal GISTs have poorer prognosis.
Recurrence rate of duodenal GISTs was higher compared with gastric GISTs [7]. Adjuvant chemotherapy with imatinib for patients with highrisk GISTs prevents recurrence [20]. In our report, patient three was classified as having high-risk GIST, which prompted adjuvant imatinib. Currently, the patient has not experienced recurrence three years postoperatively.

Conclusion
We describe three patients with duodenal GIST in whom duodenal wedge resection was performed. Our findings suggest the potential use of this resection in managing tumours not adjacent to the ampulla of Vater. In the future, we should adopt less invasive procedures for duodenal GISTs to avoid complications and improve postoperative quality of life. Moreover, giant localised duodenal GISTs may be resected by wedge resection after neoadjuvant treatment. However, future studies with larger sample size are required to validate our suggestion.

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Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

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