RELIABILITY OF HISTOLOGICAL CRITERIA IN GLYCOGEN-STORAGE-DISEASE OF THE LIVER

The histological criteria for the diagnosis of the hepatic glycogen st orage diseases (GSDs) are well recognised. However, some biopsies do n ot have the characteristic features peculiar to their type and not all biopsies with GSD changes are confirmed by enzyme analysis. We review ed the liver biopsies of 59 patients with clinically suspected GSD. Th e enzyme defects in 31 of 40 patients with GSD morphology were demonst rated by enzyme analysts. We describe the history and histology of the 9 patients with GSD morphology not confirmed by enzyme analysis, pres ent the diagnoses of the 19 patients shown not to have a GSD, and eval uate the reliability of the morphological criteria used to distinguish the types of hepatic GSD. In this study the predictive value of a bio psy with GSD changes was 90%. Mosaicism, the most sensitive criterion in the diagnosis of GSD, is not type-specific. Fibrosis does not relia bly distinguish between the GSD types and although nuclear hyperglycog enation and lipid are characteristic of type IGSD, these features are not diagnostic of any particular enzyme deficiency. The lack of morpho logical specificity implies that a complete enzyme analysis be perform ed on each biopsy. A normal enzyme analysis does not exclude a GSD and careful long-term follow-up may be necessary.