Hepatic adenoma is usually detected by imaging, typically an ultrasound or CT, as a hyperenhancing liver nodule. Given that several liver tumors appear similarly on these imaging modalities, a multi-phase contrast-enhanced imaging study such as CT or MRI may be used to provide more information. The significance of making a specific diagnosis is that, unlike other benign liver tumors such as hemangioma and focal nodular hyperplasia, hepatic adenomas<unk> ve a small but meaningful risk of progressing into a malignancy. Although imaging provides supportive information, a definitive diagnosis of hepatic adenoma requires biopsy of the tissue. Radiologic differential diagnosis * Echinococcal cyst * Focal fatty change * Focal nodular hyperplasia * Hepatoblastoma * Infiltrative liver disease * Inflammatory pseudotumor * Leiomyosarcoma * Lymphoma * Nodular regenerative hyperplasia Subtypes Hepatic adenomas may be sub-classified according to morphologic appearance by microscopy, immunohistochemical staining, and genetic mutational analysis: * Inflammatory (40%–50%) * HNF1α-inactivated (35%–40%) * β-catenin–activated - with exon 3 versus exon 7/8 mutation * β-Catenin–activated inflammatory - with exon 3 versus exon 7/8 mutation * Unclassified Although the significance of this categorization is still under research, the subtypes may indicate differential risk of hemorrhage or malignant transformation. Pathologic diagnosis Micrograph of a hepatic adenoma demonstrating a regular reticulin scaffold. Reticulin stain Hepatic adenomas are, typically, well-circumscribed nodules that consist of sheets of hepatocytes with a bubbly vacuolated cytoplasm. The hepatocytes are on a regular reticulin scaffold and less or equal to three cell thick. The histologic diagnosis of hepatic adenomas can be aided by reticulin staining. In hepatic adenomas, the reticulin scaffold is preserved and hepatocytes do not form layers of four or more hepatocytes, as is seen in<unk>  carcinoma. Cells resemble normal hepatocytes and are traversed by blood vessels but lack portal tracts or central veins. Image:Hepatic adenoma high mag.Micrograph of hepatic adenoma. H&E stain Image:Hepatic adenoma low mag reticulin.Micrograph of hepatic adenoma. Reticulin stain File:Histopathology of inflammatory<unk> .Inflammatory<unk>
Hepatocellular adenoma
Hepatoid tumor
Cavernous liver hemangioma
Fibrolamellar hepatocellular carcinoma
Focal fatty liver
Acinar cell carcinoma of the pancreas
Pancreatic serous cystadenoma
Renal–hepatic–pancreatic dysplasia