Background
Cystic hepatic lesions are commonly encountered in daily practice.
The differential diagnoses range from benign lesions of no clinical significance to malignant and potentially lethal conditions.
Hepatic cysts are the most commonly encountered hepatic lesion,
occurring in 2.5% of the general population,
and have a slight predominance in females (female-male ratio,
1.5:1).
Hepatic cysts are thought to be of biliary origin as a result of deranged development of the biliary tree,
and are typically round or ovoid structures that have an imperceptible wall.
These cysts are usually multiple in number and vary in size.
The wall of a hepatic cyst is lined by cuboidal biliary epithelium with secretory function,
and the cavity is filled with serous fluid similar to plasma; however,
there is no communication with the biliary tree.
Large cysts bigger than 4 cm are advised to be serially checked with imaging modalities and ensure stability.
Enlarging cysts may become symptomatic due to mass effect (dyspepsia,
retrosternal pain or burning sensation),
infection,
rupture or hemorrhage,
and require excluding of other diagnoses,
especially malignancies.
In the latter cases treatment options are advised.
Management
Asymptomatic simple cysts do not require intervention.
Treatment may be indicated for those that become symptomatic.
There are a number of treatment options available.
Simple aspiration is not recommended as the fluid will almost always reaccumulate inside the cyst cavity.
Sclerotherapy.
In most cases a threshold cyst diameter of 5 cm is used (>8cm in cases of polycystic liver disease).
A sclerosing agent,
such as dehydrated alcohol or a tetracycline,
is injected into the cystic cavity after complete aspiration of the contents.
It has been well documented as a simple and safe procedure.
It has been reported reduction or complete resolution of symptoms in 89.6% of cases and 98% reduction in cyst volume when followed over a 6-month period.
Multiple treatments may be required to obliterate the lesion.
A lesser response to sclerotherapy may be seen with hemorrhagic cysts or complex cysts with large amount of intracystic debris.
The most frequently reported side effects are post-procedural pain (range 5–90%) and hepatic cyst bleeding (range 2–23%),
no mortality has been reported.
Fenestration or “deroofing” is a first-line surgical technique for draining a cyst,
with either open or laparoscopic surgical approach,
and even in selected cases endoscopically using transgastric approach.
With this technique,
the cyst is opened and drained into the peritoneum.
Fenestration shows symptom reduction in 92% of cases,
with better results in anterior and subcapsular location rather than subphrenic cysts.
Wound infection,
bile leak,
chest infection,
subphrenic hematoma and prolonged drainage have all been reported as post laparoscopic complications.
In selected cases,
before the laparoscopy,
aspiration under US or CT guidance can be performed in order to assess whether symptoms are really referred to the cyst.
When AS or fenestration is not possible because of unfavorable distribution of the cysts,
segmental hepatic resection may be considered.
This procedure is warranted in cases of symptomatic and severe hepatomegaly,
in which few liver segments have multiple cysts,
but other segments are less affected.
In some cases,
dual therapy with segmental resection and fenestration of less affected segments can be performed.
Hepatic resection may be considered as an option in selected cases and should only be performed in centers with experience and expertise to reduce the risk of complications.
Polycystic liver disease (PLD) is a clinical condition which requires individualized management.
In patients with symptomatic PLD there is an unmet need for treatment.
Choice of treatment is dependent on therapeutic goal,
cyst distribution (location and size),
local expertise,
and availability.
Patients with symptoms caused by one dominant cyst are eligible for aspiration sclerotherapy.
In most cases a threshold cyst diameter of 5 cm is used (Fig 4).