Obscure Overt Small Bowel Bleed Iron Deficiency

A 68-year-old man with chronic kidney disease stage 4 and aortic stenosis presents with recurrent melena and progressive fatigue. He has undergone two negative esophagogastroduodenoscopies and two negative colonoscopies. Laboratory investigations reveal hemoglobin 7.2 g/dL, MCV 68 fL, serum ferritin 6 µg/L, and transferrin saturation 5%. Video capsule endoscopy is performed to evaluate obscure overt gastrointestinal bleeding. The structure marked **B** in the diagram—a flat, cherry-red, well-defined lesion with a central dilated vessel and radiating fern-like venules in the mid-jejunum—is most consistent with which diagnosis?