Benign and Malignant Nodular Hepatocellular Lesions
Focal Nodular Hyperplasia, Solid Type
(Tumor of the liver) The solid type of FNH occurs most commonly. Solitary lesions are observed in two thirds of individuals, while two or more lesions may be present in the remaining one third of individuals. On cut sections most solid FNH have a central fibrous stalk region (Figs.tumor of the liver, focal nodular hyperplasia with characteristic central fibrous region (arrow) and radiating fibrous cords and Histology of a central stellate scar in FNH demonstrating thick-walled vessels (arrow) of a large arterial malformation surrounded by fibrous tissue)
However, this is often absent in lesions smaller than 1 cm in diameter.
The stalk region contains an artery that typically is larger than expected considering its localization. Degenerative changes such as post-thrombotic arterial fibrosis and cholestasis may be observed in larger lesions.
Focal Nodular Hyperplasia, Teleangiectatic Type
(tumor of the liver ) This type of FNH shows multiple dilated blood spaces near the center of the lesion, so that large lesions may resemble hemangioma or peliosis.Compared with solid FNH, the arteries in the central region are small and numerous. The teleangiectatic type of FNH is usually observed in cases of multiple FNH syndrome.