Benign tumors and pseudotumors of the liver.

The pathologic and clinical aspects of benign tumors and pseudotumors of the liver are reviewed. They are classified according to the tissue of organ into epithelial (further subclassified into tumors of hepatocellular and cholangiocellular origin), mesenchymal or mixed derivation, and a miscellaneous group. Some of the tumors and pseudotumors, e.g. bile duct adenoma, small focal nodular hyperplasias and cavernous hemangiomas, and focal fatty change, are of no clinical significance. Others, such as nodular regenerative hyperplasia, hepatocellular adenoma and giant hemangioma, can be manifested by portal hypertension, hemoperitoneum or a hemorrhagic diathesis respectively. Cognizance of the histopathologic criteria for diagnosis, the radiologic features and the varied clinical manifestations are essential for management. The malignant potential of some of the benign tumors is briefly touched upon.