A0648 - Recurrent Gastrointestinal Stromal Tumor With Extensive Peritoneal Metastasis and Adhesions to the Abdominal Aorta

Sheilabi Seeburun, MD¹, Varun Vankeshwaram, MD¹, Priyaranjan Kata, MD², Omeshwar Mattarooa, MBBS^3
1Hackensack Meridian Ocean Medical Center, Brick, NJ; ²Rutgers Health Community Medical Center, Toms River, NJ; ³Dr. A.G. Jeetoo Hospital, Port Louis, Port Louis, Mauritius

Introduction: Gastrointestinal stromal tumor (GIST) is a rare tumor of gastrointestinal (GI) mesenchymal (nonepithelial) origin. We report a case of GIST to address the importance of postoperative surveillance in reducing the risk of metastases and improving the mortality rate.

Case Description/Methods: A 44-year-old male presented with one week of diffuse abdominal pain. No nausea, vomiting, fever, diarrhea, constipation, or hematemesis; status post-laparotomy for a confined jejunal mass indicative of GIST. Examination revealed a non-tender palpable RIF mass. CTA revealed multiple hypodense, heterogeneously enhancing lobulated abdominopelvic masses in the mesentery, indicating peritoneal metastases. The patient had surgical debulking, multiple tumors were discovered intraoperatively, with the largest (15 cm) in the right iliac fossa extending into the retroperitoneum, adhering to the abdominal aorta, and affecting the gastrocolic ligament. Tumors were excised and the postoperative course was uneventful. Repeat CTA revealed enhanced residual tumors arising from the gastric fundus wall and nodular lesions in the right mesentery, jejunum, and pelvis.

Discussion: GIST develops from multipotential mesenchymal stem cells and is linked to mutations in the c-KIT and PDGFRA genes. They are frequently asymptomatic, but they can bleed and cause obstructive symptoms. GIST can be malignant in up to 20% of cases. In patients with suspected GIST, computed tomography (CT) is used to assess the primary tumor. PET CT scans are extremely sensitive. These tumors usually metastasize to the liver, then to the peritoneum, as seen in this patient. Estimating the risk of recurrence after GIST resection is critical when selecting patients who may benefit from adjuvant imatinib. Tumor size, mitotic rate, and tumor origin have been identified as the most reliable predictors of recurrence and/or metastasis in these tumors. A history and physical examination every 3 to 5 months for 5 years, then annually, is recommended for a completely resected GIST, along with CTA every 3 to 6 months for 3 to 5 years, then annually. Patients receiving imatinib with locally advanced or metastatic disease should have a history, physical examination, laboratory studies, and an abdominopelvic CT scan.

Conclusion: Although GIST rarely metastasizes, the undiagnosed distant metastatic tumor 5-year survival rate is 55%. Physicians should schedule frequent follow-up visits to identify and provide necessary interventions.


Disclosures:


Sheilabi Seeburun, MD¹, Varun Vankeshwaram, MD¹, Priyaranjan Kata, MD², Omeshwar Mattarooa, MBBS³. A0648 - Recurrent Gastrointestinal Stromal Tumor With Extensive Peritoneal Metastasis and Adhesions to the Abdominal Aorta, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.