Multiple focal nodular hyperplasia.

Focal nodular hyperplasia (FNH) is a benign lesion of the liver which usually presents with one or two localizations. We report a patient with history of resection of a biliary cyst, and who had been taking oral contraceptives for the past 18 years, who had multiple localizations of FNH (more than 30 lesions). The largest lesion measured 10.5 x 11 x 12cm. The imaging characteristics of our patient were atypical. A central scar could be demonstrated only in the largest lesion, in an eccentric location. In the other lesions, no scar formations could be detected. Furthermore, imaging characteristics suggested that several of the lesions contained fat. This was confirmed by biopsy. The patient had an associated inflammatory syndrome which could not be otherwise explained. The patient was advised to stop taking the oral contraceptives. Follow-up after 2 years showed that the lesions were unchanged; the inflammatory syndrome persisted. Multiple localizations of FNH are very rare. Sometimes they are associated with malformations in other organs (vascular malformations and neoplasia, mostly of the brain). Often they occur as isolated cases, however. Usually their prognosis seems to be good.