Peliosis hepatis

Peliosis hepatis is a rare vascular condition that is characterized by multiple small, blood-filled cystic cavities within the liver. It is often idiopathic but can be caused by medications (e.g., anabolic–androgenic steroids, oral contraceptives), infections (especially Bartonella henselae in immunocompromised individuals), and malignancies. Most patients are asymptomatic, with the diagnosis frequently made based on an incidental finding on imaging. If symptoms occur, they are often nonspecific, such as upper abdominal pain or fatigue. Diagnosis can be challenging due to variable appearances on imaging, with MRI being the most sensitive modality. A definitive diagnosis often requires a liver biopsy, which has a high risk of bleeding. Management focuses on treating the underlying cause, which may lead to regression of the lesions. Interventional or surgical management is reserved for symptomatic patients or those with severe complications, such as spontaneous rupture and hemoperitoneum.

• Age ^[1]
  • More common in adults, but can occur at any age
  • Mean age at presentation: 48–52 years ^[1]
• Sex: ♂ = ♀ ^[2][3]

Epidemiological data refers to the US, unless otherwise specified.

• Medications ^[1][4][5]
  • Anabolic–androgenic steroids
  • Attenuated androgens
  • Oral contraceptives
  • Immunosuppressants (e.g., corticosteroids, azathioprine, cyclosporine)
  • Antineoplastic agents
• Infections ^[5]
  • Bacillary peliosis
  • Tuberculosis
• Malignancies ^[1][2]
  • Hematologic malignancies (e.g., lymphomas, leukemias, multiple myeloma)
  • Hepatocellular carcinoma (HCC)
• Idiopathic: approx. 50% of patients ^[3]
• Associated conditions ^[1]
  • Post-transplantation (renal or cardiac)
  • Chronic kidney disease
  • Long-term alcohol use

There are two distinct histopathologic subtypes. ^[1][5]

• Parenchymal: irregular, blood-filled cavities not lined with endothelium
• Phlebectatic: regular, spherical cavities lined with endothelium

Peliosis hepatis is often asymptomatic but may manifest with: ^[1][3]

• Upper abdominal pain
• Constitutional symptoms (e.g., fever, weight loss, fatigue)
• Hepatomegaly
• Signs of complications (e.g., hemoperitoneum secondary to rupture)

The diagnosis is challenging due to nonspecific clinical presentations and variable appearances on imaging. ^[3]

Imaging ^[1][2][5]

Lack of mass effect on adjacent vessels or bile ducts is a characteristic feature on imaging.

MRI

• Most sensitive imaging modality
• T1-weighted images: lesions are typically hypointense; may be homogeneous or heterogeneous
• T2-weighted images: lesions are typically hyperintense; may be homogeneous or heterogeneous
• Contrast-enhanced MRI: variable enhancement patterns (centrifugal, centripetal, or heterogeneous)
• Hepatobiliary phase: lesions are typically hypointense
• Diffusion-weighted imaging: usually no signs of restricted diffusion

CT

• Lesions typically appear as multiple areas of low attenuation.
• Enhancement patterns may be centrifugal or centripetal after contrast administration.

Ultrasound

The appearance of lesions depends on the surrounding liver parenchyma.

• Hypoechoic lesions: presence of hepatic steatosis
• Hyperechoic lesions: normal liver parenchyma

Additional studies ^[1]

• Biopsy
  • Often required for a definitive diagnosis
  • Open biopsy is preferred. ^[2]
• Laboratory tests: Liver function tests are often normal but may show a nonspecific increase.

• Malignant lesions ^[1][3]
  • Metastatic liver disease
  • HCC
  • Hepatic angiosarcoma
• Benign lesions ^[1][2]
  • Hepatic hemangioma
  • Hepatocellular adenoma
  • Focal nodular hyperplasia
  • Hepatic inflammatory pseudotumor
  • Pyogenic liver abscess

The differential diagnoses listed here are not exhaustive.

Management focuses on identifying and treating the underlying cause. ^[2][3]

• Discontinue causative medications.
• Treat underlying infection (e.g., antibiotics for B. henselae infection).
• For symptomatic disease or complications, consider interventional or surgical management, e.g.:
  • Surgical resection of affected liver segments for localized disease
  • Hepatic artery embolization to control hemorrhage from ruptured lesions
  • Liver transplant for severe complications such as acute liver failure

Severe complications are more common in individuals with immunosuppression or severe hematologic disorders. ^[1][5]

• Spontaneous liver rupture and hemoperitoneum
• Portal hypertension
• Cholestasis
• Acute liver failure

We list the most important complications. The selection is not exhaustive.

The prognosis is variable and depends on the underlying cause of peliosis hepatis. ^[1]

• Drug-induced: usually resolves after withdrawal of the offending agent
• Infection-related: typically regresses after antibiotic therapy
• Idiopathic: may persist or recur