Evidence for the neoplastic transformation of Von-Meyenburg complexes

Von-Meyenburg complexes (VMC) are seen frequently in the liver and are larg ely considered to be innocuous, with only ii cases reported in the literatu re of neoplastic transformation of VMCs. The authors report three cases of cholangiocarcinoma, each occurring in a background of fibrosis and nodulari ty that was reported initially as micronodular cirrhosis, Although the live rs showed cirrhosis, the central veins were often preserved and regenerativ e activity was patchy and focal. Histologic examination revealed many VMCs, and a gradual transition from VMCs to hyperplastic or adenomatous lesions and cholangiocarcinoma. The adenomatous lesions consisted of extensive repl acement of the parenchyma by tumor-like nodules of ductular proliferations without obvious features of malignancy. All three patients were older than 60 years of age and had portal hypertension. Computed tomographic scans sho wed multiple, small renal cysts in one patient. Immunohistochemical stainin g showed positivity for epithelial membrane antigen, carcinoembryonic antig en, and keratins (AE1/AE3 and CAM5.2) in tumor cells, consistent with chola ngiocarcinoma. The pattern of fibrosis and nodularity in these cases is not typical of either congenital hepatic fibrosis or usual cirrhosis. The auth ors propose that these patients represent another aspect in the spectrum of ductal plate malformations that may be modified by other factors such as a lcohol, drugs, or infection. To their knowledge, neoplastic transformation of VMCs in the background of such changes hat; never been reported before.