Master Focal Nodular Hyperplasia with Picmonic for Medicine

The exact cause of FNH remains unclear. However, it is believed to result from an abnormal blood vessel architecture within the liver, leading to localized hyperplasia (overgrowth) of liver cells.

Most patients with FNH are asymptomatic and the tumor is often discovered incidentally during imaging tests performed for unrelated reasons. When symptoms do occur, they may include abdominal pain, a palpable mass, or non-specific symptoms like fatigue.

FNH typically appears as a well-defined, solitary mass on imaging studies such as ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). The characteristic central scar, also known as a stellate scar, is a common finding.

Conservative management is the mainstay for FNH unless symptoms are severe or complications arise. Surgical resection may be considered in selected cases, particularly when diagnostic uncertainty exists or if symptoms persist despite conservative measures.

Because the lesion is usually stable or regresses over time, routine surveillance imaging to follow asymptomatic patients with FNH is not indicated.