A case presented by Li and colleagues in the Journal of Gastrointestinal Oncology details a patient who presented simultaneously with small bowel gastrointestinal stromal tumor (GIST) and intussusception.
Both these conditions are exceedingly rare. In the case of GIST, it only accounts for 0.2% of all malignancies of the gastrointestinal tract; small bowel GIST accounts for only 0.04% of all gastrointestinal tract tumors. The most common locations for their occurrence are the stomach and the small intestine.
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Intussusception is likewise a rare condition in adults and has a yearly incidence of approximately 2-3 per million population. In pediatric patients, intussusceptions are mostly idiopathic; in adults, intussusceptions are typically secondary to benign/malignant neoplasms of the gastrointestinal tract.
In a literature search using PubMed with the keywords “intussusception”, “gastrointestinal stromal tumor”, and “small bowel”, Li and colleagues reported identifying only 20 cases of intussusception caused by small bowel GISTs. This highlights how infrequently this condition has been described in medical literature. All of the cases identified underwent curative surgery after diagnosis.
We now turn our attention to the case study as presented in the Journal of Gastrointestinal Oncology.
GIST Incidentally Discovered Upon Intermittent Melena
A 63-year-old woman presented with a 9-month history of intermittent melena. Her only past medical history is hypertension. Early on in her disease, she described passing tarry stools. There was no abdominal pain, nausea, or vomiting.
Investigations were then carried out to rule out intestinal bleeding. The patient underwent some tests at a district hospital, which revealed a hemoglobin level of 80.0 g/L and a mean corpuscular hemoglobin (MCH) level of 24.2 pg. Fecal occult blood test was positive. Subsequently, an esophagogastroduodenoscopy and colonoscopy were performed, which did not reveal any gastrointestinal pathology that could explain her bleeding.
Upon pharmacological treatment, the patient’s melena improved but reappeared. At her most recent presentation, she complained of fatigue and dyspnea. She appeared to have pale skin and mucous membranes. Upon abdominal examination, she had mild tenderness around the umbilicus; there was no abdominal muscle tension, rebound tenderness, or mass. Bowel sounds were slightly audible.
Upon her latest admission, her hemoglobin dropped to 55.0 g/L and her MCH to 17.6 pg. Repeat testing revealed hemoglobin of 48.2 g/L and MCH of 17.6 pg. Crucially, an abdominal computed tomography (CT) scan revealed a jejunal intussusception.
The patient was prescribed continuous blood transfusions to improve her falling hemoglobin levels. Her hemoglobin was eventually restored to 94.0 g/L, which her physicians deemed provided safe conditions for further invasive investigations.
A small bowel enteroscopy was performed, revealing a protrusion mass (3.5 cm x 4.0 cm) in the small intestine. The mass had an ulcer at the top covered with white moss. It was 50 cm from the pylorus.
This finding prompted her surgeons to immediately perform a laparoscopic partial small bowel resection. Her surgeons found a palpable small intestinal mass, located around 50 cm from the Treitz ligament. The intussusception was revealed to have been formed by the insertion of the proximal section of the small intestine into the distal bowel.
A surgical specimen of the lesion was obtained, revealing a whitish-gray soft tissue mass (3 cm x 4 cm). The lesion had a brown area of hemorrhage and a mucosal ulcer on the surface of the tumor.
Histopathological studies revealed a small intestinal spindle cell neoplasm extending from the mucosa to the deep muscularis. Histopathologists found more than 10 mitoses per 50 high-power fields (HPF).
Surgical margin was found to be negative, and no nerve invasion or intravascular tumor thrombus was detected, the researchers noted. “Immunohistochemical (IHC) staining showed that the tumor was diffusely positive for CD117 (KIT), DOG1, and CD34 but negative for smooth muscle actin, desmin, and S100,” the study authors wrote. “Accordingly, the diagnosis of a high-risk small bowel GIST was made.”
The patient recovered without complications. On the 17th postoperative day, she was discharged. She was prescribed imatinib besylate (400 mg per day) a month after surgery due to her high risk of recurrence. At the time of writing, she was still taking imatinib regularly and remained relapse-free for 24 months after discharge.
Gastrointestinal Intussusception and GIST
“In adults, 90% of intussusceptions are secondary to a pathologic condition, which is malignant in more than 50% of cases,” Santos and colleagues wrote in Case Reports in Surgery. “The presenting symptoms are nonspecific and may be intermittent, such as abdominal pain, nausea, vomiting, and a palpable abdominal mass.”
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As mentioned, the combination of GIST and gastrointestinal intussusception is exceedingly rare, often causing a delay in diagnosis, as is in the case of the patient in this study. Nevertheless, detailed imaging studies usually point to the source of the gastrointestinal symptoms; in the case of intussusception, CT scans are particularly sensitive.
In instances of obscure gastrointestinal bleeding with/without intussusception, clinicians should consider the diagnosis of GIST and carry out appropriate investigations to rule it out. In the case of the patient in this study, she only received a GIST diagnosis 9 months after her first presentation of melena.
Once GISTs are detected, surgical resection-centered treatment is the therapeutic option of choice for primary localized GISTs, especially in patients with a significant risk of relapse.
References
Li H, Ren H, Sun H, et al. Jejunojejunal intussusception with chronic bleeding caused by gastrointestinal stromal tumor: a case report and literature review. J Gastrointest Oncol. Published online June 29, 2022. doi:10.21037/jgo-22-301
Santos SC, Leite C, Pinho H, Casimiro C. Jejunoileal GIST: a rare case of transient intussusception and gastrointestinal bleeding. Case Rep Surg. Published online April 14, 2019. doi:10.1155/2019/1492965
