Multiple Biliary Hamartomas

Multiple biliary hamartomas of the liver (also known as von Meyenburg complexes) are mulitiple tiny (1 mm - 10 mm), well-circumscribed foci of disorganized bile ductules surrounded by fibrous stroma. It is thought that they are caused by failure of involution of embryonic bile ducts (the same mechanism for polycystic liver disease).

Ultrasound will show multiple irregular hypoechoic lesions are seen throughout the liver. Smaller ductules may cause crowding of the interfaces, leading to hyperechoic lesions.

CT reveals multiple, irregular, low-attenuation lesions throughout the liver. On MRI, the lesions are well-defined, T1-hypointense, and T2-hyperintense (T2 hyperintensity is slightly less than that of water). There are usually mural nodules that are isointense on T1-weighted images and intermediate signal on T2-weighted images and which are between 1-2 mm. These nodules enhance.

Differential considerations include:

• Metastases: Lesions are usually not as uniform in shape and size as in multiple biliary hamartomas
• Microabscesses: Usually in immunosuppressed patients
• Cysts:

References

• Juchems MS, Jeltsch M, Brambs HJ. Multiple cystic liver lesions on CT: multiple biliary hamartomas. Gut. 2008 Feb;57(2):144, 251.
• Tohmé-Noun C, Cazals D, Noun R, Menassa L, Valla D, Vilgrain V. Multiple biliary hamartomas: magnetic resonance features with histopathologic correlation. Eur Radiol. 2008 Mar;18(3):493-9.