Metastatic rectal adenocarcinoma to the liver associated with focal nodular hyperplasia.

A 45-year-old female patient underwent right hemihepatectomy for metastatic rectal adenocarcinoma. Preoperative imaging demonstrated an area of focal nodular hyperplasia (FNH) in segment VIII and metastatic carcinoma in segment VI of the liver. Gross and microscopic examination of the former lesion showed features typical of FNH with an intralesional metastatic adenocarcinoma. To the best of our knowledge, this is the first reported case of metastatic adenocarcinoma located within a lesion of FNH. The possibility of a pathogenetic association behind this occurrence is discussed.