Resumen: Abernethy malformation is a rare abnormal embryological development of splanchnic venous system characterised by the presence of a congenital extrahepatic portosystemic shunt. We present a rare case of an adult male patient that was admitted with severe lower gastrointestinal bleeding, requiring multiple blood transfusions. The patient's medical history and the laboratory tests performed led to the misdiagnosis of a congenital Abernethy malformation. We present a rare case, discussing the reasons for the misdiagnosis and we conclude that management of clinical data and imaging are highly important to discard these types of congenital malformations that can mimic a portal hypertension condition. Idioma: Español DOI: 10.17235/reed.2015.3794/2015 Año: 2015 Publicado en: REVISTA ESPANOLA DE ENFERMEDADES DIGESTIVAS 107, 12 (2015), 766-767 ISSN: 1130-0108 Factor impacto JCR: 1.455 (2015) Categ. JCR: GASTROENTEROLOGY & HEPATOLOGY rank: 67 / 79 = 0.848 (2015) - Q4 - T3 Factor impacto SCIMAGO: 0.377 - Medicine (miscellaneous) (Q3) - Gastroenterology (Q3)