Previously undiagnosed genetic disease in adult patient with hepatic masses and reported history of congenital hyperinsulinism.

Glycogen storage disease type 1A (GSD1A), also known as Von Gierke's disease, is a rare autosomal recessive disorder affecting glycogen metabolism in the liver. It most commonly presents in infancy with hypoglycaemia and failure to thrive, but cases have been reported as undiagnosed until adulthood. A woman in her early 20s with diabetes mellitus presented with right upper quadrant pain and was found to have several haemorrhagic hepatic adenomas. This patient had insulin-dependent diabetes since a pancreatectomy at age 9 months due to continued episodes of hypoglycaemia and suspected insulinoma. During the hospital stay, the hepatic adenomas were embolised, but significant lactic acidosis and hypoglycaemia continued. Further workup revealed a chronic lactic acid level, during several hospital stays, of above 5 mmol/L. After cytology of hepatic tissue ruled out hepatocellular carcinoma, the patient was discharged and recommended to follow-up for genetic testing, which confirmed the diagnosis of GSD1A.