Hepatic adenomatosis is a well-known complication of glycogen storage disease type Ia (von Gierke disease). Although most of these tumors have an appearance similar to sporadic hepatocellular adenomas, unusual histologic features have been reported, including Mallory hyaline, varying degrees of fibrosis, and aggregates of neutrophils. We report the fourth case of Mallory hyaline in the adenomas of glycogen storage disease type Ia in a 28-year-old woman undergoing segmental hepatectomy for enlarging liver nodules. Other prominent findings included steatohepatitis and nonspecific granulomatous inflammation--2 findings that are commonly seen in sporadic adenomas but not, to our knowledge, previously reported in glycogen storage disease type Ia.