The ultrastructural spectrum of lysosomal storage diseases

After the important advances that have been made in the diagnosis of inherited lysosomal disorders with the help of biochemical-enzymic methods, the importance of electron microscopy for the identification and study of these conditions has apparently declined. Nevertheless, numerous specimens continue to be submitted for ultrastructural examination when lysosomal storage diseases are suspected. The article summarizes the present role of electron microscopy in this area and depicts typical specific findings in comparison with suggestive and nonspecific lysosomal changes. It is concluded that ultrastructural examination remains a useful and occasionally compulsory diagnostic method. In addition, it contributes to the identification of new diseases, the study of animal models of storage diseases, and the assessment of novel therapeutic methods such as bone marrow transplantation.