Clinical Definition
Hepatic cysts (liver cysts) are fluid-filled cavities located within the liver parenchyma, typically lined by biliary-type epithelium. They are predominantly benign and can be classified as simple cysts (congenital malformations of the biliary tree), polycystic liver disease (PCLD) (autosomal dominant inheritance), or infectious/parasitic cysts (e.g., Echinococcosis). While often asymptomatic, large cysts may cause mass effect, hemorrhage, or rupture.
Clinical Coding & Classification
| System / Category | Code(s) | Description |
|---|---|---|
| ICD-10-CM | Q44.6 | Cystic disease of liver (Congenital/Simple) |
| ICD-10-CM | B67.0 | Echinococcus granulosus infection of liver (Hydatid cyst) |
| CPT (Surgical) | 47300 | Marsupialization of cyst or abscess of liver |
| CPT (Percutaneous) | 47011 | Hepatotomy for percutaneous drainage of abscess or cyst |
| Affected System | Hepatobiliary | Structural pathology |
Epidemiology & Statistics
Simple hepatic cysts are common, with a prevalence estimated at 5% to 10% of the global population based on ultrasound screening data. There is a marked female predominance (approximately 4:1 female-to-male ratio), and prevalence increases significantly with age. Polycystic Liver Disease (PCLD) is rarer, often associated with Autosomal Dominant Polycystic Kidney Disease (ADPKD), affecting approximately 1 in 100,000 individuals.
Pathophysiology (Mechanism)
The pathogenesis depends on the cyst type:
1. Congenital Simple Cysts: Arise from Von Meyenburg complexes (biliary micro-hamartomas). These are aberrant bile ducts that fail to involute during embryonic development and lose connection with the biliary tree. The epithelial lining actively secretes fluid (mediated by secretin), causing the cyst to expand over time.
2. Parasitic (Hydatid) Cysts: Caused by the larval stage of Echinococcus granulosus. The organism forms a fluid-filled cyst with an inner germinal layer and an outer acellular laminated layer.
Standard Management Protocols
Management is reserved for symptomatic patients (pain, compression) or complications.
- Surgical/Procedural Interventions:
- Laparoscopic Deroofing (Fenestration): The standard of care for symptomatic simple cysts. Involves excising the cyst wall to drain fluid into the peritoneal cavity.
- Percutaneous Aspiration and Sclerotherapy: Injection of a sclerosing agent (e.g., Ethanol, Tetracycline) to destroy the epithelial lining and prevent fluid re-accumulation.
- Pharmacological Classes:
- Somatostatin Analogues: (e.g., Octreotide, Lanreotide) Used in severe Polycystic Liver Disease to inhibit fluid secretion by the cystic epithelium and reduce liver volume.
- Anti-parasitics: (e.g., Albendazole) Essential for the management of Hydatid cysts prior to intervention.
Healthcare Resource Utilization
Resource burdens primarily stem from diagnostic surveillance and elective interventions:
- Imaging Surveillance: Serial Ultrasound or CT imaging is used to monitor cyst growth and rule out biliary cystadenoma or cystadenocarcinoma.
- Surgical Costs: Symptomatic cases may require hospitalization for laparoscopic procedures, though recovery is generally rapid.
