Polycystic Liver Disease - Causes, Symptoms, and Treatment

Introduction:

Polycystic liver disease (PCLD) is a rare inherited condition; it is also known as ADPLD (autosomal dominant polycystic liver disease). The liver is a football-sized largest vital organ of the human body. It is just under the rib cage on the right side of the abdomen. A normal liver has a uniformly smooth appearance. In this condition, it looks like a cluster of very large grapes; the cyst grows independently in different parts of the liver. If they increase in size, they may cause discomfort and other health complications.

What Is Polycystic Liver Disease?

Polycystic liver disease is an inherited rare disease in which cysts have fluid-filled sacs formed. It is a result of ductal plate malformation of the intrahepatic biliary tree and cystic bile duct malformations from the peripheral biliary tree, which are called Von Meyenburg complexes.

Both males and females are equally affected by polycystic liver disease, but the complications and causes are more associated with females.

What Causes This Polycystic Liver Disease?

• Most of the time, this condition is associated with PKD (polycystic kidney disease).

• The individuals inherit this condition from one of the affected parents.

• The main cause of this condition is the mutation of genes; the three main genes involved in mutation are PRKCSH, LRP5, and SEC63. Patients with a mutation of PRKCSH and the SEC63 gene are more likely to get severe conditions related to polycystic liver disease than the other mutations.

• Other genes such as GANAB, ALG8, and SEC61B are three other genes potentially responsible for polycystic liver disease and investigated as a possible cause.

• Pathogenic mutation of SEC63 and PRKCSH leads to defects in processing, translocation, and folding of newly synthesized glycoproteins, which in turn, gets associated with the formation of fluid-filled cysts throughout the liver.

• Inheritance, in most cases, is in an autosomal dominant manner.

• Genetic disorder here occurs when only a single copy of an abnormal gene is inherited from either parent or results from a mutated gene of an affected individual.

• The risk of passing abnormal mutated genes from parent to offspring is 50 % for each pregnancy.

What Are the Signs and Symptoms of Polycystic liver Disease?

It is usually asymptomatic. In most cases, there are no peculiar signs and symptoms associated; in some cases, no signs are revealed till the individual’s adulthood. In cases when the liver becomes full of fluid-filled sacs and enlarged, the following signs and symptoms are seen:

• Abdominal pain.

• Feeling full.

• Bloating of the abdomen (swelling).

• Shortness of breath.

In cases with severe abdominal pain, the following symptoms are seen:

• Jaundice due to bile obstruction (yellowish discoloration of eyes, skin, and mucous membranes).

• Infection of the cyst.

• Bleeding into the cyst.

How Is Polycystic Liver Disease Diagnosed?

• Most of the cases are asymptomatic; polycystic liver disease is usually diagnosed along with the diagnosis of PKD (polycystic kidney disease).

• Screening for detecting the mutation of genes causing PCLD and PKD is done.

• MRI (magnetic resonance imaging).

• CT- scan (computed tomography).

• Ultrasound is done to check the presence and growth of the cysts.

• Molecular genetic testing to check the mutation of SEC63, LRP5, and PROKSCH.

• Blood tests to confirm the two marker levels of disease of liver and bile duct:

Gamma-glutamyltransferase (GGT) and alkaline phosphatase (ALP). There is an elevation in these two levels in patients with severe polycystic liver disease.

• Having a few cysts in the liver does not mean having polycystic liver disease because there are other more common causes of cysts in the liver. Many other factors are involved in diagnoses, such as family, age, and the number of cysts.

Diagnosis is mainly on the following basis:

• Family members with PLD are under the age of 40 years and have more than one cyst.

• Family members with PLD older than 40 years have more than three cysts.

• Family members with PLD over the age of 40 years have more than 20 cysts.

How Is Polycystic Liver Disease Treated?

Asymptomatic cases usually do not need treatment. Mild cases can be treated by medications. Treatment is dependent on the cause, site, extent of pain, location of the cyst, and other complications. The following treatment is provided in symptomatic cases:

• Cyst Fenestration: If large cysts occur on the surface of the liver, the health care provider may suggest surgery to remove the wall of the cyst, called cyst fenestration or deroofing.

• Liver Resection: Surgical removal of part of the liver is done to provide pain relief and reduce the size of the liver. If a few large cysts occur, surgical removal of them is also recommended. If many small cysts are present, liver resection is not recommended as it would not give successful results.

• Cyst Aspiration: If a cyst is blocking a bile duct or it has infected, treatment for the drainage of fluid from the cyst is done. This provides only temporary relief. These cysts often get filled up with fluid again.

• Sclerotherapy- A procedure followed after the cyst aspiration, in which the cyst is injected with alcohol (hardening substance); this prevents the cyst from refilling with fluid again.

• Liver Transplantation: In severe cases, transplantation is the only option. It is recommended for patients who experience severe abdominal pain, loss of appetite, and difficulty in eating, and it affects the overall health of the individual. This treatment is rarely recommended in the case of polycystic liver disease.

• Antibiotics - Are prescribed in cases of infections.

• Somatostatin Drug Analogs: They are recommended; it has been proved that they reduces the severity and volume of polycystic liver disease. The goal of minimizing symptoms and improving quality is to reduce the progression of cyst size. High estrogen exposure through pregnancy, oral contraceptives, and estrogen replacement therapy is associated with severe PLD. Therefore, avoiding these estrogen and progesterone-containing oral contraceptives or intrauterine devices in women is recommended.

What Is the Differential Diagnosis of Polycystic Liver Disease?

• Caroli Syndrome: A rare congenital disease associated with AR-PKD (autosomal recessive polycystic kidney disease). Enlargement of small branches of bile ducts and liver.

• Choledochal Cysts (Bile Duct Cysts): The bile duct is malformed, leading to the formation of cysts. It occurs at two to three years of age.

• Hydatid Cyst Disease: Transmitted to humans by animals through ingestion of tapeworm eggs. These eggs develop into larvae and form cysts commonly occurring in the liver but also involve lungs, brain, and visceral organs.

• Neoplastic Cysts: Abnormal tissue growth may be benign or malignant.

• Congenital Hepatic Fibrosis: This is an inherited rare disorder associated with AR-PKD.

How Can Polycystic Liver Disease Be Prevented?

No such prevention methods are there for polycystic liver disease. Research on the drugs such as Lanreotide (Samutuline) and Octreotide (Sandostatin) by IV (intravenous) or injection claims that they can decrease the cyst associated with polycystic liver disease.

Conclusion:

If you have been diagnosed with polycystic liver disease, do not panic. Most cases have

few symptoms and they live a normal life. In case of any pain associated, inform your healthcare provider, who may guide you with the appropriate treatment. Not all patients with polycystic liver disease have renal disorders. Massive hepatomegaly can lead to uncontrolled symptoms, which can complicate the situation and requires liver transplantation. The site of the cyst and its distribution may affect therapeutic options before transplantation.