Obscure Gastrointestinal Bleeding Due to a Small Intestinal Gastrointestinal Stromal Tumor in a Young Adult

The source of most cases of gastrointestinal bleeding is the upper gastrointestinal tract. Since bleeding from the small intestine is very rare and difficult to diagnose, time is required to identify the source. Among small intestine bleeds, vascular abnormalities account for 70–80%, followed by small intestine tumors that account for 5–10%. The reported peak age of the onset of small intestinal tumors is about 50 years. Furthermore, rare small bowel tumors account for only 1–2% of all gastrointestinal tumors. We describe a 29-year-old man who presented with obscure anemia due to gastrointestinal bleeding and underwent laparotomy. Surgical findings revealed a well-circumscribed lesion measuring 45 × 40 mm in the jejunum that initially appeared similar to diverticulosis with an abscess. However, the postoperative pathological diagnosis was a gastrointestinal stromal tumor with extramural growth.