Nodular regenerative hyperplasia (NRH) is a rare liver disease, characterised by the growth of

nodules Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, p ...

within the liver, resulting in

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

hyperplasia Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of Tissue (biology), organic tissue that results from ...

. While in many cases it is asymptomatic and thus goes undetected – or is only discovered incidentally while investigating some other medical condition – in some people it results in non-cirrhotic

portal hypertension Portal hypertension is defined as increased portal venous pressure, with a hepatic venous pressure gradient greater than 5 mmHg. Normal portal pressure is 1–4 mmHg; clinically insignificant portal hypertension is present at portal pressures 5� ...

(NCPH). NCPH is generally less severe than the much more common portal hypertension due to

cirrhosis Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, chronic liver failure or chronic hepatic failure and end-stage liver disease, is a chronic condition of the liver in which the normal functioning tissue, or parenchyma, is replaced ...

. Complications of NCPH can include

jaundice Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving ...

ascites Ascites (; , meaning "bag" or "sac") is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdo ...

splenomegaly Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is one of the four cardinal signs of ''hypersplenism'' which include: some reduction in number of circulat ...

, and bleeding

esophageal varices Esophageal varices are extremely Vasodilation, dilated sub-mucosal veins in the lower third of the esophagus. They are most often a consequence of portal hypertension, commonly due to cirrhosis. People with esophageal varices have a strong tendenc ...

. Most people with NRH retain normal liver function – even among the subset who go on to develop NCPH – and liver failure in NRH is uncommon. Only a small proportion of NRH patients will ever require liver transplantation. The causes of NRH are poorly understood, although it is believed to be related to abnormal blood flow in the small vessels of the liver. NRH development may be preceded by an attack of sinusoidal obstructive syndrome. Some cases are known to be caused by treatment with

azathioprine Azathioprine, sold under the brand name Imuran, among others, is an immunosuppressive medication. It is used for the treatment of rheumatoid arthritis, granulomatosis with polyangiitis, Crohn's disease, ulcerative colitis, and systemic lupus er ...

, an immunosuppressant drug commonly used to prevent rejection in organ transplantation (especially of the kidneys), and to treat various auto-immune disorders. Other drug treatments, such as with

oxaliplatin Oxaliplatin, sold under the brand name Eloxatin among others, is a cancer medication (platinum-based antineoplastic class) used to treat colorectal cancer. It is given by intravenous, infusion into a vein. Common side effects include paresth ...

, can also contribute. Medical conditions associated with NRH include

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

common variable immunodeficiency Common variable immunodeficiency (CVID) is an inborn immune disorder characterized by recurrent infections and low antibody levels, specifically in immunoglobulin (Ig) types IgG, IgM, and IgA. Symptoms generally include high susceptibility to ...

and

chronic granulomatous disease Chronic granulomatous disease (CGD), also known as Bridges–Good syndrome, chronic granulomatous disorder, and Quie syndrome, is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the react ...

. Cases may also arise after solid-

organ transplantation Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be trans ...

References

External links

{{Digestive system neoplasia Hepatology