Parreira I, Santos CA, Alves Cardoso A. Black Esophagus: A Case of Upper Gastrointestinal Bleeding in a Diabetic Patient. SPMI CR [Internet]. 2025 Aug. 1 [cited 2025 Aug. 10];3(2):66-7. Available from: https://casereports.spmi.pt/index.php/cr/article/view/259