An atypical ultrastructural pattern in Fabry's disease: a study on its nature and incidence in 7 cases

This is a report on a stored lipid atypical ultrastructural pattern in skin samples of Fabry's disease expressed exclusively in the endothelium. The pattern consisted of intersecting short crescentic tightly packed membranes with a periodicity identical to that in classical ultrastructural variants. At low magnification the lysosomal aggregates of the material resembled "sunbursts" or aggregates of densely packed squirming villus-like structures. According to results of ultrastructural, lipid, and lectin histochemical analyses including analysis of the patients' blood groups, it could be concluded that it is just a variant physical state of the otherwise typical Fabry lipid. Its origin could be attributed to impeded formation (or maintenance) of larger lipid lamellae. It was found in great amounts in skin capillaries in 2 cases, and rarely in 5 additional cases. Knowledge of this atypical ultrastructural pattern is of practical significance because it could, if prevalent, cause diagnostic problems.