Liver Cysts: Polycystic Liver Disease

Question 1

What is polycystic liver disease?

Answer 1

Polycystic liver disease is characterised by the presence of ≥20 cysts within the liver parenchyma, each of which are ≥1cm in size.

Question 2

What are the causes of polycystic liver disease?

Answer 2

They are almost invariably caused by one of the two following autosomal dominant conditions:

1. Autosomal dominant polycystic kidney disease (ADPKD)
2. Autosomal dominant polycystic liver disease (ADPLD)

Question 3

What is autosomal dominant polycystic kidney diease (ADPKD)?

Answer 3

Caused by mutations in the PKD1 (chromosome 16) and PKD2 (chromosome 4) genes, whereby 10-60% of patients will also develop have liver cysts (as the most common extra-renal manifestation of ADPKD).

Question 4

What is autosomal dominant polycystic liver disease (ADPLD)?

Answer 4

Caused by mutations in the PRKCSH (chromosome 19) or SEC63 (chromosome 6) genes; patients with this genotype will not have any renal involvement.

Question 5

What are the clinical features of polycystic liver disease?

Answer 5

The majority of patients are asymptomatic, symptoms only arising as a result of localised compression or complications.

In those symptomatic, patients will often present with abdominal pain as the cysts grow in size and hepatomegaly being present on examination. Any concurrent renal disease may also present with additional urinary tract symptoms.

Significant disease can eventually cause liver cirrhosis and portal hypertension.

Question 6

What investigations should be ordered for polycystic liver disease?

Answer 6

Most patients will have normal LFTs (ALP can become raised in a small proportion); renal function can be affected in those with renal cysts too.

Definitive diagnosis is via ultrasound imaging, demonstrating multiple cysts, usually ≥20, which have the same sonographic characteristics as simple cysts.

Question 7

How do the cysts appear in polycystic liver disease?

Answer 7

The same as simple cysts.

Anechoic, well-defined, thin-walled (often imperceptible), oval/spherical lesions with no septations, and strong posterior wall acoustic enhancement.

Question 8

Briefly describe the conservative management of polycystic liver disease

Answer 8

Asymptomatic cystic disease can be left alone and monitored, though many patients will eventually require some form of intervention due to its progressive nature. Some trials have demonstrated the short-term benefit for somatostatin analogues in symptomatic relief (acting to reduce cyst volume).

Question 9

What are the indications for surgery in polycystic liver disease?

Answer 9

Indications for surgery for cystic liver lesions are: (1)

1. Intractable symptoms
2. Inability to rule out malignancy on imaging alone
3. Prevention of malignancy

Question 10

Briefly describe the surgical management of polycystic liver disease

Answer 10

US-guided aspiration may provide temporary relief in patients experiencing pain due to cyst size, although this is not routinely performed due to fluid re-accumulation.

Laparoscopic de-roofing of cysts is the preferred technique in those experiencing symptoms or for whom there is evidence of compression of surrounding structures.

Where particular liver segments are grossly affected, then resection may be preferred, and in extreme cases, transplantation may be warranted