|Ahead of print publication
Ileal gastrointestinal stromal tumor presenting as retroperitoneal mass
Muhammer Ergenç1, Tevfik Kıvılcım Uprak2
1 Department of General Surgery, Istanbul Sultanbeyli State Hospital, Istanbul, Turkey
2 Department of General Surgery, Marmara University School of Medicine, Istanbul, Turkey
|Date of Submission||07-Jul-2021|
|Date of Acceptance||02-Sep-2021|
|Date of Web Publication||16-Nov-2021|
Department of General Surgery, Sultanbeyli State Hospital, Battalgazi Mah. Pasakoy Cd. No:60, Sultanbeyli, 34935 Istanbul
Source of Support: None, Conflict of Interest: None
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. It represents a wide range of clinical tumors with different clinical presentations, locations, and prognoses. Retroperitoneal GISTs are rarely seen and may be associated with the GI system. In this case report, we present the laparoscopic excision of retroperitoneal ileal GIST in a patient who was admitted to the outpatient clinic with abdominal pain.
Keywords: Gastrointestinal stromal neoplasm, gastrointestinal stromal tumor, GISTs, ileum, retroperitoneal neoplasms
| > Introduction|| |
Gastrointestinal (GI) stromal tumors (GISTs) are the most common mesenchymal tumors originating from Cajal cells, the pacemaker cells responsible for regulating peristalsis in the digestive system. The most common symptoms in patients are abdominal pain, GI bleeding, and intestinal obstruction. Ileal gist can be symptomatic with the mass effect it creates, and it can also cause an abscess, perforation, and acute abdomen. In this case report, we present the laparoscopic excision performed in a patient admitted to the outpatient clinic with abdominal pain and was found to have a retroperitoneal mass.
| > Case Report|| |
This is a case of 58-year-old female patient, who had been admitted to the general surgery outpatient clinic complaining of low abdominal pain. The patient's abdominal physical examination was normal. The patient had a lumbar disc hernia surgery about 5 years ago. There was no history of illness or medication. Her body mass index was 21.1 kg/m2, and she smoked 40 packs of cigarettes a year. Complete blood count and biochemistry parameters were in the normal range.
Abdominal ultrasonography (US) showed a well-circumscribed hypervascular solid lesion of 19 mm × 19 mm × 21 mm in the right lower quadrant. Intravenous contrast-enhanced computed tomography (IV-CT) abdominal tomography showed a 21 mm × 23 mm mass in the right lower quadrant [Figure 1], adjacent to the psoas muscle [Figure 2].
|Figure 1: Axial image of the abdomen computed tomography scan showing a mass (white arrow)|
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|Figure 2: Coronal image of the abdomen computed tomography scan showing a mass adjacent to the psoas muscle (white arrow)|
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Laparoscopic exploration was performed. There were no other pathologies found on laparoscopic exploration. Retroperitoneal space was entered in the ileocecal region. The retroperitoneal area was exposed, and the surrounding tissue around the mass was dissected [Figure 3]. The ureter was preserved. Approximately 3 cm of a lesion, which was determined to originate from the ileum wall, was resected from the intestinal wall side with negative margins with a linear stapling device (Endo GIA™-Medtronic, Blue Staple 3.5 mm) [Figure 4]. It was carefully removed from the abdomen with an endobag. The operation was completed without any complications.
|Figure 3: Intraoperative view shows a mass (thick arrow) and ileum (thin arrows)|
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|Figure 4: Intraoperative view shows mass resection (thick arrow) and appendix (thin arrow)|
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Her postoperative period was uneventful, and she was discharged on the 3rd postoperative day. Pathological examination revealed a GIST (3 cm × 3.5 cm × 2.5 cm) had invaded the submucosa layer of the ileum. A low-grade GIST was reported based on the histological findings. Mitotic count was <5/50 high-power fields. On immunohistochemistry, the tumor cells were diffusely positive for CD 117 (c-kit), DOG-1, and CD 34, while it was negative for Spinal muscular atrophy. Ki-67 proliferation index was 10%. No further treatment was recommended by the multidisciplinary tumor board meeting. On the follow-up, no recurrence was observed in the 3rd postoperative year.
| > Discussion|| |
GISTs are mesenchymal tumors of the GI tract that expresses the KIT (CD117, stem cell factor receptor) protein, as detected using immunohistochemistry. The prevalence of gist is 10–15/million. The median age of occurrence is 60, and it affects both genders to be equal. GISTs can be detected in the entire GI tract; in order of frequency; stomach (55.6%), small bowel (31.8%), colorectal (6%), and other regions (6.6%).
Although the clinical symptoms and signs of GISTs are generally nonspecific, tumors may cause GI bleeding, intestinal obstruction, pelvic mass, acute pain like appendicitis, tumoral rupture, and acute abdomen. In this case, the mass was found by the differential diagnosis of nonspecific lower abdominal pain.
Retroperitoneal GISTs are rarely seen. They may develop primarily in this region or may be associated with the GI system. They are generally located in the peripancreatic area and are detected incidentally. In our case, the tumor's location was in the terminal ileum, however, it was extended to the retroperitoneal region.
With the increase and widespread use of imaging techniques, GISTs can be diagnosed in the early stages without developing complications. Small GISTs appear as a well-defined homogeneous mass but large GISTs tend to be inhomogeneous and can be demonstrated with findings such as necrosis and calcifications. Central fluid attenuation is usually seen in malignant GISTs. However, it is difficult to make a definitive diagnosis preoperatively by imaging in retroperitoneally located GISTs. It is confused with other mesenchymal tumors such as leiomyosarcoma, malignant fibrous histiocytoma, fibrosarcoma, and liposarcoma in this area. In this case, imaging modalities showed a mass in the ileocecal area, but the differential diagnosis could not be made via US and IV-CT. Therefore, laparoscopic excision of the tumoral mass was performed.
Small intestinal tumors have a significantly worse prognosis according to gastric tumors with similar size and mitotic activity. Small intestinal GISTs ≤5 cm with low mitotic activity are predictably benign (3% frequency of progressive disease), and tumors with >5 mitoses per 50 HPF (high power fields) are predictably malignant (>50% tumor-related mortality). In this case, no recurrence was observed in the 3-year follow-up, in line with this. In the prognostic model by the Armed Forces Institute of Pathology, the prognosis is affected by mitotic rate, primary site, tumor size, and the completeness of resection. According to modified National Institutes of Health risk stratification, intraabdominal tumor rupture is with the high-risk category and needs adjuvant therapy.
In GIST treatment, R0 resection is recommended without perforating the mass. In selected patients, laparoscopic resection can be applied to these tumors due to their biological behavior predisposes them to curative resection without the need for wide margins or extensive lymphadenectomy. Additional advantages of laparoscopy are less trauma and rapid recovery. Segmental bowel resection or if appropriate just tumor excision is applicable because limited resections with negative margins are usually sufficient.,,
As in our case, GISTs can also be detected incidentally in imaging performed with nonspecific abdominal pain. GIST should be kept in mind in patients diagnosed with retroperitoneal masses with radiological imaging. In selected cases, laparoscopic mass excision can be safely performed without any complications.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]