[Von Meyenburg complex associated with adult polycystic liver disease]

The von Meyenburg complex (bile duct hamartoma) is a rare developmental disorder, manifested by multiple bile ducts. The polycystic liver disease is a rare congenital anomaly which may remain undiscovered until adult life, occurring more frequently in women. It is mostly asymptomatic, but sometimes surgical intervention is necessary. In the majority of cases, it is combined with cysts in the kidney and, rarely, in other organs as well. The cysts may vary in diameter from 1 mm to 20 cm, or even more.

A 55-year-old woman underwent surgery based on clinical diagnosis: suspected Echinococcus liver cyst. Liver biopsy was performed, and a parenchymal tissue of 6.5x4x3 cm, with a cyst with a diameter of 2.5 cm, was resected. Within the cyst lumen there was a necrotic, mushy, yellow contents. Microscopically examined, it showed plenty of cholesterol crystals. The wall of the cyst consisted of hypocellular connective tissue. In the surrounding liver parenchyma, there were cystical formations of the same structure, measuring 1-2 mm. Also, there were some multiple bile duct hamartomas. The ducts were encircled by a delicate connective tissue.

These changes correspond to von Meyenburg complex, i.e. biliary microhamartoma combined with adult polycystic disease. In our case, in the wall of the cyst there were numerous cholesterol crystals, pointing to its retention character and, probably, to the mechanism of its origin. After degeneration of biliary epithelium, the cyst wall grew very thick, due to proliferation of the connective tissue evoked by the aggressive chemical contents of the bile. Frequent development of cholangiocarcinoma within the cyst wall also points to long-term chemical irritation.