The occurrence of gastrointestinal stromal tumors (GISTs) in the small intestine is rare, and a case of wandering small intestinal stromal tumor has been rarely reported to date. Dissemination of this case can help inform future diagnosis and effective treatment.

A 68-year-old patient presented to us with tarry stools. Computed tomography showed a mobile tumor moving widely within the abdominal cavity. As the laboratory data showed a low range of red blood cells and an immediate surgery was not indicated, we performed digital subtraction angiography and embolization to achieve hemostasis. Surgical resection was performed after the patient’s condition improved. The tumor was successfully removed laparoscopically. Histological examination revealed submucosal GIST with infarction, which was of intermediate-risk, with mitotic count < 1 per 10 high-power field. Immunohistochemical studies revealed the following: CD117+, Dog1+, CD34+, SMA+, S100-, CK-, Des-, SOX-11-, STAT6-, Ki67 Hotspots 10%+. The patient was ultimately diagnosed with wandering small intestinal stromal tumor.

When a highly vascularized tumor is clinically encountered in the small intestine, the possibility of stromal tumors should be considered. However, when the tumor cannot be visualized at its original location, the possibility of tumor migration is considered.

Gastrointestinal stromal tumors (GISTs) originate from the interstitial cells of Cajal, which are dependent on stem cell factor receptor interaction, and express both KIT and CD34. Immunohistochemistry plays an important role in differentiating GISTs from leiomyomas and neurogenic tumors[1]. Histopathologic findings are the gold standard for diagnosing GISTs[2]. They become symptomatic if they enlarge, causing ulceration, bleeding (e.g., hematemesis, melena), and iron deficiency anemia. Tumors larger than 2 cm carry an increased risk of malignancy and hence are resected. The role of laparoscopy in the resection of GISTs is constantly being affirmed. Imatinib is a selective KIT inhibitor that achieves sustained clinical benefit and objective efficacy in most patients with GISTs. Tumors of intermediate- and high-risk require imatinib for 3 years after radical resection[3]. GISTs are the most common mesenchymal tumors of the gastrointestinal (GI) tract. However, wandering small intestinal stromal tumors are extremely rare. Herein, we report a case of a 68-year-old man presenting with a small intestinal mass that was diagnosed as a suspected wandering small intestinal stromal tumor. Computed tomography (CT) with contrast and digital subtraction angiography (DSA) of abdomen revealed an aberrant mass that wandered from the right upper quadrant to the left upper quadrant, before returning to the right lumbar region of the abdomen. The location of the mass varied from visit to visit. Surgery was performed, and the diagnosis was confirmed by histopathology. This study aims to enhance our understanding of this rare and intriguing condition.

Histopathological examination confirmed the presence of submucosal GIST measuring 5.2 cm × 3.6 cm × 3.4 cm in size with infarction. It was of an intermediate-risk, with mitotic count < 1 per 10 high-power field, spindle unit type, and with an intact coating. Immunohistochemical (IHC) studies revealed the following: CD117+, Dog1+, CD34+, SMA+, S100-, CK-, Des-, SOX-11-, STAT6-, Ki67 Hotspots 10%+. These results indicated that the tumor originated from the jejunal stroma of GIST (Figure 3) and were consistent with the results of the CT examination. The patient was ultimately diagnosed with wandering small intestinal stromal tumor (clinical staging: T3NOMO).

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Figure 3 Histopathological and immunohistochemical. A: Histopathological examination of the resected specimen (hematoxylin and eosin; × 40) showing submucosal stromal tumor with intact capsule, infarction, spindle shaped cells, and nuclear division less than 1/10 hibernation promoting factor. Immunohistochemical test results revealed the following (× 200); B: CD34+; C: CD117+; D: Dog1+.

Two weeks later, tumor excision was performed when the patient’s physical condition improved with small bowel resection. Laparoscopically, a 1-cm incision was made layer by layer into the abdomen at the lower edge of the navel. On exploration, the entire abdominal intestine was widely congested and edematous; the intestinal lumen was filled with a large amount of serous bloody fluid; and the local intestinal tube was adherent to the surrounding abdominal wall. Moreover, the tumor had been adherent to the intestinal wall with a longer mesentery. The mass was located approximately 30 cm distal to the ligament of Treitz. We excised the tumor; end-to-end anastomosis of the small intestine was achieved with a straight closed device, and abdominal closure was performed layer by layer.

The patient recovered well after surgery. Imatinib (400 mg daily) was prescribed postoperatively and the patient was followed up. The current basic situation is good.

GISTs are the most common malignant subepithelial lesions of the GI tract [4]. The stomach and small intestine are the most common locations. Small intestinal stromal tumors account for approximately 20%–30% of the incidence of GISTs[5]. GISTs are different from neurogenic tumors and leiomyomas in initial presentation, biological behavior, and immunophenotype[6]. However, IHC is conclusive in determining the histology of the tumor, based on proto-oncogene c-kit (CD117) and CD34 positivity to diagnose GISTs. GISTs measuring > 5 cm in diameter are at a risk of rupture, and most of the GISTs that originate in the small intestine measure > 5 cm in diameter at the time of diagnosis[7]. The most common symptom is gastrointestinal bleeding, which can be life-threatening and requires urgent intervention, such as surgery or catheter embolism[8]. In recent years many studies have reported that GISTs commonly co-exist with other primary tumors, which can involve either the GI tract or other extra-GI sites. It is not yet clear if a causal association exists for the concomitant occurrence of GISTs with other malignancies, or if this is merely coincidence[9].

Tumors measuring larger than 2 cm should be removed because of the increased risk of malignancy. Recurrence, tumor size, mitosis count, site of origin, and tumor rupture are the risk factors for GISTs[10]. Our patient had intermediate-risk of recurrence; therefore, we administered imatinib therapy 1 mo after the surgery. Careful follow-up of our patient is needed due to the risk of recurrence. Although wandering small intestinal stromal tumors are extremely rare, several reports on wandering intestinal tumors[11], mesenteric tumors, uterine fissures, and migraine mesothelioma are currently available in the literature. A wandering mass is usually related to the presence of a wandering spleen, owing to the laxity of its normal ligamentous attachments[12,13]. Similarly, the mesentery of the small intestine is relatively long, which permits mobility to a certain extent. Some of the factors that induce or contribute to a change in the position of the intestinal lumen include distention due to food, gastrointestinal peristalsis, or position changes. Any mass in the lumen is affected by gravity. However, such a spectacular change in location as in our patient, is extremely rare and may suggest a bowel origin. CT examination can accurately show the location, size, growth patterns, presence of necrosis, contrast enhancement, neoplastic angiogenesis, and potential metastasis[14]. Small GISTs (< 5 cm) appear as homogeneous lesions with persistent enhancement in contrast CT. Large tumors (> 5 cm) typically appear heterogeneous, contrast enhanced, and associated with cystic changes, necrosis, and ulceration[15]. Surgical treatment is preferred in the absence of metastasis[16]. DSA has important value in the detection of hemostasis for acute small intestinal bleeding (to distinguish a tumor or vascular origin)[17]. In this case, the tumor traveled widely, accompanied by its vascular pedicle derived from the superior mesenteric artery branch. Patients with these lesions typically present with internal hernia, torsion, and/or acute abdominal pain[18]. However, our patient had no symptoms of obstruction or torsion; similar cases have not been reported in the literature.

In patients with acute or chronic intestinal hemorrhage whose diagnoses are ambiguous, we should consider the possibility of GISTs. CT is a valuable tool to visualize these contrast-enhancing lesions. The wide variations in the embryonic development of the small intestine and its mesentery must be taken into account in anticipating tumor behavior arising from that location. When the tumor cannot be visualized at its original location, we should consider the possibility of tumor migration.

We thank the patient and his family for giving permission for his inclusion in this study. Thank my family for their support.