Hepatocellular carcinoma in a patient with focal nodular hyperplasia

Background: Focal nodular hyperplasia is an uncommon liver tumour that typically requires no therapeutic intervention. Case outline: A 43-year-old woman with a 20-year history of oral contraceptive use presented with symptomatic bilateral liver masses. Biopsy revealed hepatocellular carcinoma in the right hemiliver and focal nodular hyperplasia in the left hemiliver. At operation, the patient was noted to have multiple liver nodules bilaterally, and all intraoperative biopsies were consistent with focal nodular hyperplasia including a biopsy taken from the region that demonstrated carcinoma preoperatively. Because of the earlier biopsy results and the patient's preoperative symptoms, a right hemihepatectomy was performed. Final pathology revealed hepatocellular carcinoma directly adjacent to an area of focal nodular hyperplasia, as well as multiple other areas of hyperplastic liver tumour. Discussion: Although focal nodular hyperplasia is believed to be benign, few studies have followed patients with this tumour beyond three years. Longer-term follow-up studies are needed to determine the natural history of focal nodular hyperplasia, potentially focussing on a subset of patients with either diffuse tumours or prolonged oral contraceptive use.