• Colon
• liver

Focal nodular hyperplasia (FNH) is the second most common benign neoplasm of the liver after haemangioma. It occurs predominantly in women of child-bearing age (female/male, 8/1–12/1). The lesions are often multiple and usually involve the right liver lobe. Although the aetiopathogenesis of FNH is not clear, it has recently been thought to be a non-neoplastic, hyperplastic response to a congenital vascular malformation. The role of oral contraceptive use has long been discussed, but today most investigators agree that the use of oral contraception does not induce the formation of FNH, but may increase the size of the nodules. FNH is also related to well-known vascular diseases, such as the hereditary haemorrhagic telangiectasia (Rendu–Osler–Weber disease) and the congenital absence of the portal vein.1 However, there is still no known association between FNH and familial adenomatous …