Primary Polytopic Developmental Field Defect in a Patient with GI Bleeding
A 52-year-old male presents to the clinic complaining of bloody stool since this morning. He has a past medical history of surgery for anal atresia as a neonate and osteoarthritis. He occasionally takes NSAIDs over the counter for his osteoarthritis. His vital signs on admission are normal, but physical examination reveals mild scoliosis of the cervical and thoracic spine. He does not use tobacco or drink alcohol. He is hospitalized for further evaluation. Colonoscopy and upper gastrointestinal endoscopy are performed, but no bleeding site is found. On the second hospital day, a capsule endoscopy is performed and bleeding from the small intestine is detected. On the third day, the patient develops shock due to massive bleeding. Thus, emergency transcatheter arterial embolization is scheduled to control the bleeding. Computed tomography angiography (CTA) is performed before the procedure and it shows an hypoplastic left external iliac artery with abnormal blood flow from the left common iliac into the internal iliac artery.
Which of the following is the most likely diagnosis of the patient's findings?