Malignant Transformation of Hepatic Adenoma in Glycogen Storage Disease Type-1a: Report of an Exceptional Case Diagnosed on Surveillance Imaging.

Hepatocellular adenoma is a heterogeneous group of benign neoplasms arising from hepatocellular cells and can be subclassified into four major groups based on genotypic and phenotypic characteristics. These four subtypes are hepatocyte nuclear factor (HNF) 1α-inactivated, β-catenin-activated, inflammatory, and unclassified adenomas. Immunohistochemistry studies have demonstrated that since β-catenin-activated adenomas have a higher risk of malignant transformation, the identification of the subtype of adenoma remains crucial in patient management. However, malignant transformation of hepatic adenoma without β-catenin overexpression can be seen in 30-65% cases. We report a case of malignant transformation of hepatic adenoma without overexpression of β-catenin in a 31-year-old man with a known glycogen storage disease (GSD) Type-1a, which was diagnosed on surveillance magnetic resonance imaging (MRI). The MRI showed a mild interval increase in one lesion with relative stability of the other adenomas. The lesion was presumed to be suspicious for a hepatocellular carcinoma (HCC) and was confirmed on pathology.