The Endoscopic Appearance of a Gastrointestinal Stromal Tumor in a Pediatric Patient

Abstract

Gastrointestinal Stromal Tumor (GIST) is a mesenchymal tumor that is rare in children. We report a case of GIST in a pediatric patient presenting with melena, anemia and gastric submucosal masses. A 16 year old female presented after an episode of syncope preceded by one episode of melena. Physical exam was normal except for hemoccult positive stool. Labs included a Hg of 6.1 g/dl; CMP and coagulation studies were normal. She was transfused with 2 units of PRBC and emergent EGD was performed. EGD demonstrated 3 submucosal sessile masses in the gastric antrum ranging in size from 1–3 cm with normal overlying mucosa except for one of the lesions, which was ulcerated. Endoscopic biopsies stained positive for CD 117 and were consistent with GIST. Radiologic workup with CT, MR, and PET imaging demonstrated the endoscopically visualized masses. MRI and PET imaging also revealed a solitary 1 cm lesion within the liver. She underwent partial gastrectomy and open biopsy of the hepatic lesion. Histology confirmed GIST with hepatic metastasis. She received postop chemotherapy consisting of Imatinib Mesylate, and has done well without disease recurrence with a follow up of nine months. Typically with GIST, EGD will demonstrate a normal surface mucosa and a firm, smooth, yellowish submucosal mass, which can be ulcerated. In some cases these tumors can be missed because of their frequent submucosal and extraluminal growth. This case, to our knowledge, is one of the first reports of the endoscopic appearance of GIST in a pediatric patient. Endoscopic ultrasound (EUS) is an important aid to differentiate submucosal masses seen by EGD. By EUS GISTs will typically have a hypoechoic appearance and will originate from the muscularis propria. EUS was unnecessary in our patient because the biopsies obtained by EGD were deep enough to provide a pathologic diagnosis. Although a rare entity in children, we conclude that the possibility of GIST should be considered in pediatric patients with endoscopically visualized submucosal gastric masses.