Small bowel gastrointestinal stromal tumor: a retrospective study of 32 cases at a single center and review of the literature

Abstract

Background: Gastrointestinal stromal tumor (GIST) is a rare tumor of the small bowel, which can be difficult to diagnose and has a varied clinical outcome.

Purpose: This is a retrospective review of the diagnosis, management, and clinical outcome of 32 patients diagnosed with primary small bowel GIST from a single center and a comparison of the findings with previously published cases.

Patients and methods: Retrospective review of data from patient clinical records, endoscopic and imaging findings, surgical procedures, tumor histology and immunohistochemistry, and clinical outcome was conducted.

Results: Data of 32 patients with a median age of 56 years including 50% men and women were reviewed. The majority (29/32) were symptomatic at presentation, with the main symptom being gastrointestinal bleeding (15/32). Imaging detection rates included ultrasound (0%), magnetic resonance imaging (0%), computed tomography (54.8%), computed tomography angiography (71.4%), and double-balloon enteroscopy (88.9%). The mean tumor diameter was 5.3 cm; 4 tumors were located in the duodenum, 21 in the jejunum, and 7 in the ileum. Based on the tumor size and mitotic index, 5 (15.6%), 15 (46.9%), 0 (0%), and 12 (37.5%) patients were classified into very low-risk, low-risk, intermediate-risk, and high-risk groups. Immunohistochemistry showed positive expression for CD117 (100%), CD34 (81.2%), DOG1 (93.8%), smooth muscle actin (37.5%), S100 (9.4%), and desmin (6.2%). Twenty-five patients (78.1%) were treated with open surgical tumor resection; seven patients (21.9%) underwent laparoscopic surgery. Postoperative complications that occurred in seven patients (21.9%) were resolved with conservative management. Four patients were treated with postoperative imatinib. At median follow-up of 30 months, two patients were died.

Conclusion: The findings from this case series, combined with the findings from previously published cases, provide an update on the current status of the diagnosis and the therapeutic approaches that might lead to improvement in prognosis for patients who present with primary small bowel GIST.

Keywords: clinical outcome; diagnosis; gastrointestinal stromal tumor; prognosis; small bowel.

Figure 1

Gastrointestinal stromal tumors arising from the ileum. Notes: (A1–B3) A 63-year-old male presenting with hematochezia. (A1) Transabdominal ultrasound image shows a 6.6×8.2 cm² well-defined, heterogeneous and hypoechoic mass above the urinary bladder. (A2) Axial plain CT image shows a soft tissue mass located in the pelvis. (A3) Coronal plain CT image shows a lobulated pelvic mass (arrow). (B1) Axial T1WI shows an isodense mass (arrow). (B2) Axial contrast-enhanced T1WI shows the mass with markedly heterogeneous enhancement (arrow). (B3) Axial T2WI showing the mass with heterogeneous hyperintensity. (C1–C3) A 48-year-old male presenting with abdominal mass. (C1) Transabdominal ultrasound image shows a 5.2×5.7 cm² well-defined, heterogeneous and hypoechoic mass in the left lower abdomen. (C2) Axial contrast-enhanced CT image shows an irregular mass with markedly heterogeneous enhancement (arrow). (C3) Coronal contrast-enhanced CT image shows an exophytic mass arising from small bowel with inhomogeneous enhancement (arrow). Abbreviations: CT, computed tomography; WI, weighted imaging.

Figure 2

Gastrointestinal stromal tumors arising from the duodenum. Notes: (A1–B4) A 60-year-old male with an incidentally abdominal space occupying lesion during routine checkup. (A1) Axial plain CT image shows a 5.1×5.2 cm² slightly heterogeneous mass. (A2) Coronal plain CT image shows a well-defined, irregular mass (arrow). (A3) Axial T1WI shows the mass with slight hyperintensity. (A4) Axial T2WI shows the mass with heterogeneous hyperintensity. (B1) Histopathology shows the tumor cells are composed of spindle cells with a high mitotic count (>5 mitoses/50 HPFs; HE staining; original magnification ×100). (B2) A week after the operation, repeated CT scanning demonstrates the patient complicated with intestinal obstruction. (B3) Ten days after the operation, abdominal plain X-ray reveals the patient still accompanied with partial intestinal obstruction. (B4) The mass was resected, and the patient was started on adjuvant imatinib. Follow-up contrast-enhanced CT scanning 10 months after treatment, shows that there is no local recurrence and distant metastasis. (C1–C4) A 56-year-old female presenting with abdominal mass. (C1) Axial plain CT image shows a 6.7×8.7 cm² mass in the right upper quadrant of the abdomen. (C2) Axial contrast-enhanced CT image shows the mass with markedly heterogeneous enhancement. (C3) Coronal contrast-enhanced CT image shows a well-defined, oval mass with inhomogeneous enhancement, but suggestive of a pancreatic tumor. (C4) Histopathology shows the tumor cells are composed by mixed spindle and epithelioid cells with a low mitotic count (≤5 mitoses/50 HPFs; HE staining; original magnification ×100). Abbreviations: CT, computed tomography; WI, weighted imaging; HPFs, high-power fields; HE, hematoxylin and eosin.

Figure 3

SB GISTs-associated abdominal pain and distension. Notes: (A1–B3) A 49-year-old male presenting with abdominal pain. (A1) Coronal plain CT image shows the patient with partial intestinal obstruction on admission, but no primary tumor is found. (A2) Five days after admission, axial CTA image shows a 1.6×2.5 cm² well-circumscribed intraluminal tumor with intense enhancement (arrow). (A3) In the above level, intussusception of the small bowel is seen (arrow). (B1) Coronal CTA image shows bowel wall edema and thickening with the intraluminal tumor. (B2) Coronal CTA image shows the feeding artery of the tumor (arrow). (B3) 3D reconstruction of CTA image shows the tumor (arrow) is supplied by branch vessels from the superior mesenteric artery. (C1–C3) A 57-year-old male presenting with abdominal distension. (C1) Coronal CTA image shows a pelvic mass in close association with the bowel loops, confirmed to be arising from the ileum at surgery. (C2) Axial CTA image shows an 8.0×10.0 cm² well-defined mass with smooth outline. (C3) Sagittal CTA image shows the feeding artery of the tumor (arrow) from the branch of superior mesenteric artery. Abbreviations: SB GISTs, small bowel gastrointestinal stromal tumors; CT, computed tomography; CTA, computed tomography angiography.

Figure 4

SB GISTs-associated gastrointestinal bleeding. Notes: (A1–A4) A 57-year-old female with a duodenal GISTs presented with melena. (A1) Axial plain CT image shows a 2.0×2.2 cm² well-defined, isodense mass (arrow). (A2) Axial contrast-enhanced CT image shows the mass with markedly heterogeneous enhancement in the duodenum (3rd part). (A3) DBE shows a round tumor with central ulceration. (A4) Macroscopic appearance of the surgical specimen. (B1–B4) A 46-year-old male with a jejunal GISTs presented with melena. (B1) Coronal plain CT image shows a 3.5×4.0 cm² isodense mass (arrow) arising from small bowel. (B2) Axial plain CT image shows the mass (arrow) with extraluminal and intraluminal components. (B3) DBE shows a tumor with engorged vessels and deep ulcer in the jejunum (middle part). (B4) Gross appearance of the operative specimen shows adherence of the adjacent bowel to the tumor (arrow). (C1–C4) A 56-year-old female with a jejunal GISTs presented with hematochezia. (C1) Coronal plain CT image shows an exophytic mass (arrow) arising from the jejunum. (C2) Axial plain CT image shows a 2.5×3.0 cm² well-defined, round mass (arrow). (C3) DBE shows a protrusion with mucosal erosion in the jejunum (upper part). (C4) Gross appearance of the operative specimen shows an exophytic tumor with the bleeding point (arrow), indicative of the bleeding source. Abbreviations: SB GISTs, small bowel gastrointestinal stromal tumors; CT, computed tomography; DBE, double-balloon enteroscopy.

Figure 5

SB GISTs-associated gastrointestinal bleeding. Notes: (A1–A5) A 23-year-old female with a jejunal GISTs presented with melena. (A1) Coronal plain CT image does not reveal the primary tumor due to poor bowel preparation. (A2) CE shows a blurry mass and dark-red blood residue in the jejunum (middle part). (A3) DBE shows the jejunal blood clots. (A4) DBE shows a 2.5×2.5 cm² round, smooth tumor with umbilication. (A5) Histopathology shows the tumor cells are composed of spindle cells with a low mitotic count (≤5 mitoses/50 HPFs; HE staining; original magnification ×100). (B1–B5) A 81-year-old male with a jejunal GISTs presented with melena. (B1) Coronal plain CT image does not reveal the primary tumor due to polymorphous intestine. (B2) Coronal CTA image shows a 1.5×1.6 cm² well-defined tumor with marked enhancement (arrow), which is supplied by jejunal branch from the superior mesenteric artery. In this case, radiological report suggests a hemangioma. (B3) Axial CTA image shows the tumor (arrow) with extraluminal and intraluminal components. (B4) CE shows a protruded lesion in the jejunum (upper part). (B5) DBE shows the intraluminal component of the tumor with mucosal erosion. (C1–C5) A 58-year-old female with a jejunal GISTs presented with melena. (C1) Axial plain CT image seems to reveal an intestinal soft tissue mass (arrow). (C2) Axial contrast-enhanced CT shows a 1.0×2.2 cm² tumor with a dumbbell-like appearance and with marked enhancement (arrow). (C3) Coronal CTA image shows a small bowel tumor with markedly peripheral enhancement (arrow). (C4) Coronal CTA image shows the tumor (arrow) is supplied by vessels from the superior mesenteric and iliac arterial territories. (C5) DBE shows a round, smooth tumor in the jejunum (upper part). Abbreviations: SB GISTs, small bowel gastrointestinal stromal tumors; CT, computed tomography; CTA, computed tomography angiography; CE, capsule endoscopy; DBE, double-balloon enteroscopy; HPFs, high-power fields; HE, hematoxylin and eosin.

Figure 6

Ileal GISTs and immunohistochemistry. Notes: A 55-year-old male with an ileal GISTs presented with melena. (A1) Axial plain CT image does not reveal the primary tumor due to polymorphous intestine. (A2) Axial contrast-enhanced CT image shows a 1.3×1.8 cm² tumor (arrow) with marked enhancement in the arterial phase. (A3) DBE shows the intraluminal component of the tumor with engorged vessels. (A4) Gross appearance of the operative specimen shows the extraluminal component of the tumor (arrow). (B1) Histopathology shows the tumor cells are composed of spindle cells with a low mitotic count (≤5 mitoses/50 HPFs; HE staining). Tumor cells are strongly positive for CD117 (B2), CD34 (B3), and DOG1 (B4). Tumor cells are negative for SMA (C1), which is positive in vascular wall. S-100 (C2) and Desmin (C3) are negative in tumor cells. Ki-67 (C4) is positive in some of the tumor nuclei (global index 2%). (Original magnification: B1 ×100; B2–C4 ×200). Abbreviations: GISTs, gastrointestinal stromal tumors; CT, computed tomography; DBE, double-balloon enteroscopy; HPFs, high-power fields; HE, hematoxylin and eosin; SMA, smooth muscle actin.

Figure 7

Jejunal GISTs and duodenal adenocarcinoma. Notes: (A1–A4) A 54-year-old male with an incidentally jejunal GISTs during CT scanning for acute diarrhea. Axial (A1) and coronal (A2) plain CT images do not reveal the primary tumor due to intestine loops overlaps. Axial (A3) and coronal (A4) contrast-enhanced CT images show a 1.8×2.0 cm² exophytic tumor (arrow) with marked enhancement, but suggestive of a hemangioma. (B1–B4) A 57-year-old female with a duodenal adenocarcinoma presented with abdominal pain and vomiting. (B1) Axial contrast-enhanced CT image shows a 3.0×4.5 cm² tumor (arrow) with heterogeneous enhancement in the duodenum (4th part), but suggestive of a GISTs. (B2) DBE shows the intraluminal part of the tumor with obvious lumen stenosis. (B3) Macroscopic appearance of the surgical specimen. (B4) Histopathology shows the tumor to be a moderately poorly differentiated adenocarcinoma (HE staining; original magnification ×100). Abbreviations: GISTs, gastrointestinal stromal tumors; CT, computed tomography; DBE, double-balloon enteroscopy; HE, hematoxylin and eosin.