- Transformation of normal hepatic parenchyma into small regenerative nodules, also known as micronodular transformation.
- Should not be confused with regeneration nodules found in cirrhotic patients
- Thought to be related to altered blood flow; obstructive portal venopathy causes ischaemia, which in turn leads to hyperplasia of hepatic acini with adequate blood flow in order to compensate for atrophied hepatocytes.
- NRH has been associated with immunological and haematological disorders, cardiac and pulmonary disorders, several drugs and toxins, neoplasia and organ transplantation.
- It has been suggested by some that NRH is a premalignant condition, although others think that NRH is a condition secondary to HCC or its treatment.
- The majority of patients are asymptomatic, although some patients have signs of portal hypertension.
- The nodules have variable echogenicity on ultrasonography and are often hypodense on CT without significant enhancement.
- Unfortunately, even MRI may not be helpful to distinguish the lesions as they are often small and difficult to characterise.
- Therefore, histological examination is necessary to make the diagnosis of NRH
- A correct diagnosis is often difficult using percutaneous needle biopsy, and in these cases laparoscopically guided liver biopsy or wedge biopsy for diagnosis may be considered.
- The management depends on the presenting symptoms, but should at least focus on treating the underlying condition.
- If there is portal hypertension, treatment options include medication or sometimes portosystemic shunt procedures, but it may also be necessary to treat complications such as ascites or oesophageal varices.
- Liver failure is a rare complication for which liver transplantation may be the only solution.