When Every Test Fails: Multifocal Grade 1 Ileal Neuroendocrine Tumors Causing Transfusion-Dependent Obscure Overt Gastrointestinal Bleeding.

Small bowel neuroendocrine tumors (NETs) rarely present as obscure overt gastrointestinal bleeding (OGIB), causing significant diagnostic challenges. We report a 56-year-old man who presented with OGIB that required approximately 50 units of packed red blood cells during a 6-week hospitalization. Multimodal evaluation, including computed tomography angiography, tagged red blood cell scan, video capsule endoscopy, computed tomography enterography, provocative mesenteric angiography, balloon enteroscopy, and octreotide scan, failed to identify a source. Exploratory laparotomy identified 3 mid-ileal nodules with histopathology revealing well-differentiated grade 1 neuroendocrine tumors. Bleeding resolved following resection. This case highlights the diagnostic and therapeutic role of surgical exploration in refractory OGIB.