Nodular regenerative hyperplasia of the liver: description of two cases.

Nodular regenerative hyperplasia (NRH) of the liver is a condition of unknown origin, rarely occurring in children, usually accidentally discovered, described in association with a variety of clinical conditions and drugs. Confusion with other types of hepatic masses may pose a problem and for this reason NRH is considered a "tumor-like lesion." Histologically it consists of single or multiple regenerative foci. Hepatic failure and rupture of the liver have been rarely described as complications in adults, and not in children, and malignant transformation has not been demonstrated. Neither surgical removal nor other treatment is needed. These features are described as they were found in two patients we encountered.