Adenomas of the liver and focal nodular hyperplasia (FNH) are benign hepatocellular affection and their distinguishing in a needle biopsy sample and sometimes also in a surgical specimen causes often a problem. Although it might seem that the differentiation of the benign conditions is of a low value for the clinicians and also for the patients, the opposite is true. The risk of life-threatening bleeding and risk of the malignant transformation of adenomas leads to request accurate diagnosis of these conditions. New genetic methods followed by immunohistochemical detection of several antigens enables more accurate distinction not only of the two main groups of FNH and adenomas, but allows also to distinguish subsets of adenomas with varying risk of malignant transformation. Therefore, to determine the subtype of adenoma represents now essential part of a biopsy diagnosis. Identification of the subsets of adenomas allows an individualized treatment with resection in high-risk forms and, on the other hand, allows avoiding liver resection in the case of small liver mass with a low risk of malignant transformation.
Adenoma Focal Nodular Hyperplasia