Ectopic liver tissue in the kidney: case report and literature review

The presence of ectopic liver tissue has been reported in various abdominal and extra-abdominal sites, most often in the gall bladder. Other rare sites include the retroperitoneum and the adrenal gland, which are anatomically closer to the kidney. However, our literature search did not reveal any reports of ectopic liver tissue within the kidney. We present such a case, detected incidentally during a fetal autopsy histologic examination, and we review the possible developmental aspects causing it. Ectopic liver is usually asymptomatic, although it can carry pathology similar to the orthotopic liver. It can be associated with other congenital anomalies and, rarely, can be the cause for clinical emergencies. The most significant implication, however, is development of hepatocellular carcinoma because of an increased predisposition compared with the native liver. Hence, we suggest that ectopic liver in the kidney should be considered by histopathologists, even in unsuspecting cases.