14. Focal nodular hyperplasia

Organ: Liver

Description:

On the front of the preparation can we see a well-circumscribed brownish lesion. The lesion has a central scar.

On the back of the preparation can we see a poorly circumscribed greyish lesion.

Diagnosis: Front: Focal nodular hyperplasia. Back: Liver metastasis

Causes:

Focal nodular hyperplasia:
- Oral contraceptive use

Theory:

This preparation contains two different, unrelated lesions. On the front is the lesion of a focal nodular hyperplasia (FNH). FNH is the second most prevalent benign lesion of the liver, but unlike most other liver lesions, FNH is not due to neoplasia but rather hyperplasia (and as such is not considered a tumour in most cases). It has no malignant potential and is normally asymptomatic, so it’s usually not treated. FNH produces a lesion with a characteristic star-shaped scar in the centre.

The second lesion is on the back and is a liver metastasis.