Polycystic liver disease (PLD) is a rare genetic condition in which there are several cystic changes in the liver. Cysts are fluid filled sacs that take up the space of normal liver cells and can cause abdominal discomfort if they grow too big in size, although it is not a life threatening disease. In general, polycystic liver disease is of two types: Isolated form of polycystic liver disease and autosomal dominant polycystic kidney disease. Isolated form of Polycystic liver disease is a condition in which cysts are found in liver only whereas in autosomal dominant polycystic kidney disease the cysts are found both in the kidneys as well as the liver. This variant of polycystic kidney disease is more common with about 90% of all polycystic liver disease patients suffering from this variant of the disease.
What Causes Polycystic Liver Disease?
The primary cause of polycystic liver disease is considered hereditary. Isolated polycystic liver disease is caused due to mutation in SEC63 and PRKCSH genes that help in the processing of proteins. Autosomal dominant polycystic kidney disease is a result of mutation in PKD1 and PKD2 genes. SEC63, PRKCSH, PKD1 and PKD2 mutations cause dysregulation of polycystin 1 and polycystin 2 proteins, which are responsible for the regulation of fluid secretion and growth of epithelial cells. Thus, mutations in these proteins result in cyst formation, both in kidneys and liver, through fluid secretion and growth of epithelial cells forming cysts.
What Are The Primary Risk Factors For Polycystic Liver Disease?
The primary risk factor for developing a condition like polycystic liver disease is a family history of this disease in one of the family members. As the condition is primarily autosomal dominant, one copy of the defective gene from either parent is good enough for the baby to get this disease. Other significant risk factor is the gender which in this case is being a female as they are more susceptible for developing polycystic liver disease when compared to men. It is attributed to female sex hormones (such as estrogen) that might be responsible for growth of liver cysts. Increased risk is associated with pregnancy and use of oral contraceptive pills as well as hormonal replacement therapy in postmenopausal women. Another important risk factor is age as the number and severity of cysts increase with increasing age.
What Are The Symptoms Of Polycystic Liver Disease?
In general, when the liver cysts are small, the individuals are asymptomatic. However, when the cyst size is too large, the main polycystic liver disease symptom is abdominal distention and swelling due to large cyst size along with hepatomegaly. Other symptoms that are associated with large cyst include abdominal discomfort, shortness of breath, back discomfort and early signs of fullness after eating. On occasions, liver cyst impinges vessels of liver leading to portal hypertension, pseudo Budd-Chiari syndrome and variceal bleeding. On rare occasions, the cysts may be infected and will present with symptoms of fever and focal pain in the liver or can also transform into cystic carcinoma. When cyst has developed into cystic carcinoma, patient will present with pain as well as weight loss. It is rare in cases of polycystic liver disease to develop signs of liver problem such as jaundice, ascites, variceal bleeding or hepatic encephalopathy.
The diagnosis is confirmed after an imaging (ultrasound, CT scan or an MRI), which will typically show hepatomegaly along with numerous macrocysts in liver and/or kidneys depending on the type of polycystic liver disease. The treatment modality of polycystic liver disease includes antibiotics if the cyst/cysts are infected, cyst puncture and drainage with a catheter and laparoscopic/open cyst fenestration (creating a window in the cyst to drain the cyst). If the above interventions are not successful or patient has advanced polycystic liver disease then either liver resection or liver transplantation can be opted. Liver transplantation and liver resection are extremely rare as most of the patients are managed by other procedures.