BACKGROUND: Abernethy malformation (AM), or congenital absence of portal vein (CAPV), is a very rare disease which tends to be associated with the development of benign or malignant tumors, usually in children or young adults.

CASE REPORT: We report the case of a 21-year-old woman diagnosed with type Ib AM (portal vein draining directly into the inferior vena cava) and unresectable liver adenomatosis. The patient presented mild liver dysfunction and was largely asymptomatic. Living donor liver transplantation was performed using a left hemiliver graft from her mother. Postoperatively, the patient attained optimal liver function and at 9-month follow-up has returned to normal life.

CONCLUSIONS: We consider that living donor liver transplantation is the best therapeutic solution for AM associated with unresectable liver adenomatosis, especially because compared to receiving a whole liver graft, the waiting time on the liver transplantation list is much shorter.

Keywords: Adenoma - surgery, Follow-Up Studies, Liver Neoplasms - surgery, Liver Transplantation, Living Donors, Portal Vein - abnormalities, Time Factors, Vascular Malformations - surgery, young adult