Nodular regenerative hyperplasia

Nodular Regenerative Hyperplasia

Nodular Regenerative Hyperplasia (NRH) is a rare liver condition characterized by the diffuse transformation of normal hepatic parenchyma into small regenerative nodules without significant fibrosis. This condition can lead to non-cirrhotic portal hypertension and is often associated with various systemic diseases and medications.

Pathophysiology

NRH is believed to result from uneven blood flow within the liver, leading to atrophy of some hepatocytes and compensatory hyperplasia of others, forming nodules. Unlike cirrhosis, NRH does not involve significant fibrosis, which distinguishes it from other nodular liver diseases.

Causes

The exact cause of NRH is unknown, but it is associated with several conditions and factors, including:

• Autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis.
• Hematological disorders like myeloproliferative neoplasms.
• Use of certain medications, including chemotherapy agents and immunosuppressants.
• HIV/AIDS and other chronic infections.

Clinical Presentation

Patients with NRH may be asymptomatic or present with signs of portal hypertension, such as:

• Splenomegaly
• Esophageal varices
• Ascites
• Hepatic encephalopathy

Diagnosis

The diagnosis of NRH is challenging and often requires a combination of clinical, laboratory, and imaging studies. A definitive diagnosis is usually made through a liver biopsy, which shows nodular transformation without significant fibrosis.

Imaging

Imaging studies such as ultrasound, CT scan, and MRI may show nodular liver surface and signs of portal hypertension but are not specific for NRH.

Histology

Liver biopsy is the gold standard for diagnosis, revealing nodular regenerative changes in the absence of fibrosis.

Treatment

There is no specific treatment for NRH. Management focuses on treating the underlying condition and complications of portal hypertension. This may include:

• Beta-blockers for variceal bleeding prevention.
• Diuretics for ascites management.
• Endoscopic interventions for variceal bleeding.

Prognosis

The prognosis of NRH varies depending on the underlying cause and the presence of complications. Patients with well-controlled underlying conditions and minimal portal hypertension may have a favorable outcome.

See Also

• Portal hypertension
• Liver cirrhosis
• Hepatology

External Links

• [American Liver Foundation](https://www.liverfoundation.org)
• [National Institute of Diabetes and Digestive and Kidney Diseases](https://www.niddk.nih.gov)