Only 5% of all primary GI tract tumors are small bowel origin tumors [9]. It is difficult to diagnose the small bowel tumor because symptoms are often absent or non-specific. Small bowel origin GIST is a rare tumor that is also difficult to diagnose. A review of 18 cases of intussusception secondary to GIST found that approximately 39% (7/18) of GISTs were within the small bowel. None of them had massive bleeding symptoms [2,3,4,5,6]. Thus, our case is the first reported and extremely rare manifestation presented as small bowel intussusception with massive bleeding from GIST.
Normally, endoscopic examination is considered first in patients with hematochezia or melena symptoms to identify the bleeding focus site. But, in patients with atypical abdominal pain, such as intussusception, AP-CT can be considered as primary strategy. In this case, endoscopy was performed first because there was massive bleeding than with normal intussusception. When the endoscope failed to identify the site of bleeding, AP-CT was performed immediately. AP-CT image showed the intussusception with jejunal GIST requiring an emergency operation.
Classically, GIST is not easy to cause intussusception or bowel obstruction because it grows exogenously into the abdominal cavity and spread rarely into adjacent organs [4]. Intussusception with massive bleeding from GIST is more extremely rare, too. Also, if GISTs have a mucosal ulcer at well-developed organs of blood vessels such as the stomach, massive bleeding can occur [10]. The jejunum is a well-developed organ. In this case, GIST originated in the jejunum with accompanying intussusception and massive bleeding triggered by ulceration. Ulcers involving sites of excessive blood circulation can lead to life-threatening outcomes.
Mitotic index and tumor size are well-known parameters used to stratify GIST into low, intermediate, and malignant categories. However, the classification does not fully indicate the risk of GIST malignancy and only reflects the degree of aggressiveness. Even a small GIST with a low mitotic index may increase the risk of recurrence or metastasis to other organs and sites. Therefore, currently, GISTs are considered as malignant neoplasms, and strict criteria based on specific parameters have yet to be established [11].
However, Novitsky et al. reported that mitotic index, tumor size, tumor ulceration, patient age, and necrosis are key factors that significantly influence tumor recurrence [12]. Further, Miettinen et al. reported that the small intestinal GISTs show more aggressive features compared with the gastric GISTs of similar size and mitotic index; however, tumor ulceration has limited effect on patient’s prognosis [13, 14].
Surgical intervention is not always indicated for GIST. However, surgical resection is necessary to determine the predisposing factors. Adult intussusception is an indication for surgical resection. In this study, GISTs of small bowel origin associated with ulceration and intussusception were resected. Post-surgery, the patient was defined as a low-risk category for recurrence despite the presence of GISTs in the small intestine with ulceration. The patient was under surveillance according to the Korean guidelines for GIST [15].