Unfused Liver Segments: a Case Report of an Unknown Phenotype of the Conradi-Hünermann-Happle Syndrome.

BACKGROUND: Since its description in 1957, Couinaud`s classification of the segmental organization of the liver has remained valid. However, recent investigations by 3-dimensional computed tomography suggest a significant variability of the vascular anatomy and segment volume. Here, we report a surprise finding during the laparoscopic cholecystectomy of a patient with Conradi-Hünermann-Happle syndrome, in whom the liver segments were not fused.

CASE REPORT: Laparoscopic cholecystectomy was performed because of recurrent biliary pancreatitis in a 47 year-old male patient, who had been diagnosed with Conradi-Hünermann-Happle syndrome. Upon direct view, the liver parenchyma appeared normal, but liver segments were separated and connected by fibrous bridges containing vascular structures, only. Since the hilar anatomy was unclear, an open cholecystectomy was performed without technical difficulties and the postoperative course was uneventful. Postoperatively, magnetic resonance imaging was performed, which revealed a trifurcation of the portal vein and a right bile duct draining into the left main duct. Intersegmental signal alterations corresponded to the fibrous bands seen during laparoscopy.

CONCLUSIONS: The intraoperative findings of this case confirm the segmental organization of hepatic anatomy proposed by Couinaud. The first description of such an unusual anatomical variant in an extremely rare genetic disorder strongly suggests an association with the genetic background of the syndrome. The established abnormalities of cholesterol biosynthesis in patients with Conradi-Hünermann-Happle syndrome may well explain the observed liver anomaly, which is a novel phenotype of this syndrome. Based on this case, we suggest a potential involvement of the mutation in the emopamil-binding protein gene in liver development and regeneration.