Surgery remains the therapeutic option of choice for duodenal gastrointestinal stromal tumors (GISTs), provided that they are still at a resectable stage. The standard surgical treatment is the complete removal of the lesion with an adequate margin.
Small intestinal tumors can be broadly classified into 5 categories: epithelial, nonepithelial, polyps, secondary tumors, and malignant lymphomas. GISTs fall under the category of “nonepithelial” tumors; sarcomas also fall under this category and comprise around 14% of all nonepithelial small intestinal tumors.
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The challenges with duodenal GISTs are 2-fold. First, symptoms can be initially vague and become prominent only when the tumor becomes sizable. The most commonly reported symptoms are melena/anemia, followed by abdominal pain; the presence of additional constitutional symptoms such as weight loss and anorexia may point physicians towards the possibility of a cancer diagnosis much quicker.
Second, the anatomy of the duodenum and its surrounding structures are notoriously tricky to navigate surgically. This is especially the case if the tumor invades other surrounding organs, such as the pancreas.
“[Duodenal GISTs] may pose surgical challenges due to their unique but complex pancreaticoduodenal location of the gastrointestinal tract near the ampulla of Vater, pancreas, mesenteric blood vessels, biliary and pancreatic ducts,” Dr. Lim wrote in the World Journal of Gastrointestinal Surgery. “The current surgical options of resectable primary D-GISTs vary with increasing complexity depending on the location, size, and involvement of surrounding structures.”
Therefore, it is imperative that any discovered duodenal GIST is staged correctly prior to surgery. To achieve this, surgeons usually perform an esophagogastroduodenoscopy to better visualize the lesion and its surroundings; of particular importance is whether any mucosal ulcerations, masses, or bleeding can be observed. One of the cardinal rules of duodenal GIST removal is to reduce the risk of bleeding and perforation as much as possible.
Other imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT), are also carried out to stage the cancer and act as a precautionary measure in case anything is missed during endoscopy. A careful analysis of the tumor with imaging studies can help ensure that surgeons enter the surgical theatre armed with as much useful information as possible.
Managing a Bleeding GIST
In the Ochsner Journal, Harris and colleagues presented the case report of a patient who underwent surgery for a duodenal GIST. The report involves a 70-year-old female who presented to a hospital after experiencing presyncopal episodes and melenic stools. Blood investigations revealed that she was anemic (hemoglobin levels of 8.8 g/dL). She was immediately transfused with 4 units of packed red blood cells and started on oral proton-pump inhibitors.
An esophagogastroduodenoscopy revealed a Forrest classification 1B duodenal bulb ulcer with a slightly protuberant appearance. This was obviously a matter of urgent concern, and the ulcer was treated with injected epinephrine. CT scans revealed a duodenal bulb thickening without any apparent mass.
Biopsies demonstrated gastric heterotrophs with no evidence of malignancy. She was also negative for Helicobacter pylori. The patient’s bleeding resolved, and she was discharged.
One month later, she presented again to attend an endoscopy appointment. The esophagogastroduodenoscopy revealed that the duodenal ulcer had healed; however, it also showed a 23.8 mm x 16.8 mm lesion in the duodenal bulb, with no evidence of invasion into surrounding structures. Pathological studies showed that the lesion was consistent with GIST. CT scans revealed that cancer had not metastasized.
The patient was started on neoadjuvant imatinib 400 mg daily. Her surgeons planned further endoscopy/CT studies to evaluate the appropriateness of surgical resection.
Following the Evidence
In this case study, the patient’s initial presentation was melena, confirmed by her anemic status. This was revealed to be caused by a duodenal ulcer. Her GIST could have been entirely missed if she did not have a follow-up endoscopy.
“Initial [esophagogastroduodenoscopy] and CT findings could have easily been attributed to duodenal peptic ulcer disease for which follow-up endoscopy is not routinely recommended given the low risk of malignancy,” Harris and colleagues wrote. “However, because of the high index of suspicion on the part of the referring physicians, duodenal GIST was diagnosed.”
The instincts of the referring physician proved to be correct, allowing the patient’s physicians to start preparing for future steps. Imatinib is often prescribed as an adjuvant chemotherapy drug if the tumor is large, ruptured, or at a non-gastric site (which carries a higher risk of recurrence). Sunitinib is typically used as a second-line drug.
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This case report highlights 1 of the 2 challenges raised earlier regarding duodenal GISTs: they can sometimes easily evade notice because they produce no symptoms or, in this patient’s case, result in bleeding that can be feasibly attributed to another source. However, evidence-based suspicion can guide physicians in paying closer attention to certain cases; in this instance, a repeat endoscopy after the bleeding has cleared revealed a discreet GIST that was previously missed.
Ultimately, surgical resection can only be initiated if a GIST is first clearly visualized, staged, and downsized (if necessary). Therefore, care for patients with duodenal GISTs starts from the very moment a patient walks in with suspicious gastrointestinal symptoms.
References
Lim KT. Current surgical management of duodenal gastrointestinal stromal tumors. World J Gastrointest Surg. 2021;13(10):1166-1179. doi:10.4240/wjgs.v13.i10.1166
Harris PS, Romano J, Russ KB, Shoreibah MG, Baig KRKK. Gastrointestinal stromal tumor: GIST, another duodenal ulcer. Ochsner J. 2020;20(2):236-238. doi:10.31486/toj.18.0167
