Bleeding ileal schwannoma resulting in severe anemia requiring massive blood transfusion: A rare case report

Introduction: Melena is a common symptom of schwannoma of the small intestine, a rare type of tumor. Even more rare is schwannoma of the small intestine that requires a massive blood transfusion due to hemorrhage. Herein, we report such a case successfully treated with surgical resection. Presentation of case: A 72-year-old woman presented to the previous hospital with melena. The patient was taking antiplatelet drugs for a previous cerebral infarction. The patient had progressive anemia due to continuous melena. Thus, she needed a massive blood transfusion with 12 units of packed red blood cells within 1 week of admission. A diagnosis was not possible based on the esophagogastroduodenoscopy and colonoscopy findings. Therefore, the patient was referred to our hospital for further examination and treatment. Computed tomography (CT) showed a well-circumscribed tumor with hyperattenuation in the small intestine, and double-balloon endoscopy (DBE) revealed a submucosal tumor (SMT) in the ileum. The patient was diagnosed with a bleeding gastrointestinal stromal tumor (GIST) and underwent laparoscopic partial resection of the ileum. The histopathological findings revealed spindle-shaped cell growth and a peritumoral lymphoid cuff. Furthermore, immunohistochemistry demonstrated that the tumor cells were negative for c-kit and CD34 but positive for S100 staining. Finally, the patient was diagnosed with ileal schwannoma. The postoperative course was uneventful, and the patient was discharged on postoperative day 10. Conclusion: This report describes an extremely rare case of ileal schwannoma requiring massive blood transfusion. Furthermore, it highlights that schwannomas of the small intestine can cause severe anemia, especially in patients receiving antiplatelet drugs.