Intramuscular capillary abnormalities in a case of myotonic dystrophy (Steinert's disease).

The structural study of a muscle biopsy from a case of myotonic dystrophy showed endothelial cell and pericyte alterations, and infiltration of lymphocytes, macrophages and mast cells. The histopathological picture was similar to that observed in the muscular compromise of some autoimmune diseases. These findings are interesting because although the aetiology of myotonic dystrophy is still obscure, it has been suggested that in the origin of this disease could be involved either primary muscle fibre damage or that myotonic dystrophy is neurogenic, propositions apparently not directly connected with a relation cause-effect to intramuscular capillary abnormalities.