Focal nodular hyperplasia K76.8

Edmondson, 1958

Focal, polyclonal, non-specific hyperplasia of hepatocytes. Second most frequent benign liver tumor (Marrero JA et al. 2014).

Focal-nodular hyperplasia is defined as a hamartoma (malformation) of the liver. Apparently, however, hyperplasia can also occur reactively.

In 60 % of patients focal-nodular hyperplasia develops with the use of oral anticonceptives. Pathogenetically, the relationship between the intake of estrogen-containing preparations and the development or increase in size growth is not fully understood (Chandrasegaram MD et al. 2015). Stopping hormone therapy can lead to regression.

A vascular malformation is also being discussed. Some authors interpret FNH as "hyperplastic-regenerative reaction in liver tissue to regionally increased perfusion" through isolated large-caliber arteries (Wanless et al. 1985). Such processes are known to occur in vascular malformations of other organs.

As triggering factors, various other factors have also been identified. Drugs such as thiopurines, various other chemotherapeutic agents and antiretroviral drugs have been described as triggering factors (Ghabril M et al. 2014).

Women between the ages of 20 and 50 are particularly affected.

As a rule, these are solitary nodes (multifocal FNH is described) with a diameter < 5 cm. Mostly discovered as a random finding in imaging procedures (ultrasound, CT, MRI), which were induced for other reasons. In the contrast medium sonogram evidence of a central artery with wheel spoke structure of the parenchyma. Only rarely is the FHA clinically conspicuous due to its size with upper abdominal pain.

Possibly slight increase in liver values.

The most widely used sonography is basically the primary imaging procedure of diagnostic examination sequences. The combination of contrast medium-supported computer tomography with sonography can be used for further confirmatory imaging diagnostics. Only rarely is histological clarification necessary.

In extremely rare cases, bleeding or rupture of an FNH may occur.

Malignancy is not described by the FNH. Surgical removal is only necessary in case of very large nodules (>5cm) or in case of severe abdominal pain.

Increased concordant occurrence with vascular anomalies such as: telangiectasias, arteriovenous fistulas, Osler's disease, congenital portocaval anastomoses (in patients with congenital portocaval anastomosis, cases with an FN are increasingly observed), hemangiomas (Wanless et al. 1989)

1. Chandrasegaram MD et al (2015) Estrogen hormone receptors in focal nodular hyperplasia. HPB (Oxford) 17:502-507.
2. Ghabril M et al (2014) Drug-induced nodular regenerative hyperplasia. Semin Liver Dis 34:240-245.
3. Marrero JA et al (2014) ACG clinical guideline: the diagnosis and management of focal liver lesions. Am J Gastroenterol 109:1328-1347
4. Wanless IR et al (1985) On the pathogenesis of focal nodular hyperplasia of the liver. Hepatology 5: 1194-1200
5. Wanless IR et al (1989) Multiple focal nodular hyperplasia of the liver associated with vascular malformations of various organs and neoplasia of the brain: a new syndrome. Mod Pathol 2: 456-462.