What it means

FNH is a lump of normal liver cells that have grown in a disorganized way, probably in response to an unusual artery inside it. It is not cancer. Many have a central scar, a star-shaped strip of tissue that carries the feeding vessels. On MRI with a liver-specific contrast agent, FNH typically holds on to the contrast as normal liver does, which helps tell it apart from other lumps.

When it matters

FNH is most often found by chance in women in their 20s to 40s. It does not turn into cancer and very rarely bleeds or causes symptoms. When MRI shows the classic features, no treatment or follow-up is usually needed. If the appearance is not typical, another scan may be done, and occasionally a biopsy, to tell it apart from a liver adenoma, which is managed differently.

Questions to ask your doctor

  • Does the MRI show the classic features of FNH, or is it uncertain?
  • Do I need any follow-up scan, or can it simply be left alone?
  • Does taking birth control pills or being pregnant affect it?