Vacuolated lymphocytes in type II glycogenosis--a diagnostic approach?

Using electron microscopy, glycogen-filled lysosomes were found in peripheral lymphocytes in 5 cases of the infantile form of glycogenosis type II. In two infants whose blood smears were available, the ultrastructural demonstration of this pathognomonic storage corresponded to well-delineated vacuoles detected by routine light microscopy. Detection of such vacuoles in peripheral lymphocytes by light microscopy and demonstration of glycogen-filled lysosomes by electron microscopy could be a simple and harmless tool for diagnosing the classical form of type II glycogenosis.