Gastrointestinal Stromal Tumor (GIST) in a Young Adult: A Rare Presentation and a Multidisciplinary Approach.

A gastrointestinal stromal tumor is a rare gastrointestinal tumor of mesenchymal origin. We present a rare case of a 32-year-old male patient with a history of iron deficiency anemia who presented with nocturnal cramping abdominal pain, nausea, non-bloody vomiting, loss of appetite, and weight loss. The patient had no significant family history of cancer. Prior imaging showed gastric distension with chronic inflammatory changes, but a scheduled esophagogastroduodenoscopy (EGD) was not done due to loss of follow-up. On admission, the patient was tachycardic with anemia. An abdominal CT scan showed new areas of gastric wall thickening with edematous wall thickening at the gastric cardia. An EGD revealed deep gastric ulcers with elevated edges with central necrosis, raising concerns for malignancy. A biopsy of the gastric cardia confirmed a high-grade stromal tumor with the aid of a DOG1 test; the gastric cardia was KIT-positive in immunohistochemical testing but negative for Helicobacter pylori. The tumor was staged at pT3N0. He was treated with surgical resection with negative margins and imatinib therapy. Postoperative surveillance showed no evidence of malignancy and the patient experienced a positive response to treatment with stable hemoglobin levels and significant weight gain.