Hepatic cysts classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview[edit | edit source]

Classification[edit | edit source]

Bile Duct Hamartomas[edit | edit source]

Bile duct hamartomas (BDH) – also referred to as ‘simple cysts’ and ‘von-meyenberg complexes’ – are uncommon but not rare. They are benign and do not transform into malignancies. Small cysts can be found in as many as 7.3% of people referred for abdominal MRI while giant, symptomatic cysts are present in 0.4% of the population referred for such imaging.^[1] BDH are more common in women, in a ratio of 4:1 or more, and the average age of presentation is 60 years old. ^[2][3] Pain is, by far, the most common presentation, but patients have also complained of jaundice, edema and have presented, rarely, with a ruptured cyst.

Cystadenoma and Cystadenocarcinomas[edit | edit source]

Less common than BDH, the largest published series describing these lesions found 18 cystadenomas and 4 cystadenocarcinomas at a large institution in Cleveland over the course of 17 years. Roughly 85% are reported in women, aged 41 to 53 years old.^[4][5] The key clinical difference with cystadenomas compared to BDH is the chance that they will become malignant.

Polycystic Liver Disease[edit | edit source]

Polycystic liver diseases are genetic disorders that can be either liver-specific or part of a broader disease complex known as autosomal dominant polycystic kidney disease (ADPKD). The defects in pure polycystic liver disease are those of glycoprotein metabolism and thus the lesions are fluid-filled biliary epithelial cysts full of the byproducts of errant oligosaccharide metabolism.^[6][7][8] There is recent evidence to suggest that the development of cysts is further exacerbated by a secretin mediated increase in cyclic AMP that generates increased biliary fluid prodcution^[9]

The Autosomal Dominant Polycystic Kidney Disease is caused by two mutations in the ADPKD-1 gene on chromosome 16 and ADPKD-2 on chromosome 4. Polycystins, the product of these genes, are proteins expressed on the epithelium of renal tubules, hepatic bile ductules and pancreatic ducts that appear to play crucial roles in the mechanosensation of cilia. ^[10][11] In other words, these mutations limit the ability of the cells in these tissues to detect and react to structural distortions, leading to cystic degeneration.

Hydatid Cysts[edit | edit source]

Hydatid disease – Echinococcosis – is caused by the larval form of Echinococcus granulosus, has a worldwide distribution and is endemic in many developing countries. It is isolated to the liver in 50-70% of patients and the lungs in 20-30%.^[12] If symptomatic, patients typically present with pain/discomfort, an abdominal mass, fever or, very rarely, cyst rupture.

References[edit | edit source]

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