A study of multiple biliary hamartomas based on 1697 liver biopsies

Multiple biliary hamartomas (MBHs) are rare benign malformations of the intrahepatic bile ducts. There are only a handful of clinical studies based on large populations on the incidence of MBHs.

A series of 1697 consecutive liver needle biopsies was examined for the occurrence of MBHs.

A total of six patients (0.35%, four men and two women, a 2 : 1 ratio) were confirmed by histology to have MBHs. Of the total of 1697 patients, 59 (3.5%) patients were younger than 18 years of age, 828 patients (48.8%) were between 18 and 38 years of age, and 810 patients (47.7%) were older than 38 years of age. Of the six MBHs patients, one was 17 years of age and the other five patients were older than 39 years of age. The median (range) age of the patients was 42 (17-63) years. Although nearly half (48.8%) of the biopsied patients were between 18 and 38 years of age, no MBH was found in this group. All MBHs patients were diagnosed with fibrosis/cirrhosis by initial ultrasound scanning; however, only two patients were confirmed to have cirrhosis by histological examination. Of those two patients with cirrhosis, one had concomitant congenital hepatic fibrosis and the other had concomitant cirrhotic hepatitis B. The latter patient developed hepatocellular carcinoma 1 year after biopsy. No kidney cysts were found in any of the six MBHs patients. MRI scanning was performed in four patients and the results were consistent with the histological diagnosis.

MBHs are not common in patients who undergo liver biopsy and, in this study, the occurrence was higher in the older age group.