[Electron microscopic examination of the morphogenesis of the elastic fibre in elastosis senilis and pseudoxanthoma elasticum (author's transl)].

We undertook to investigate the elastic and collagenous fibers of senile elastosis (s.E.) and pseudoxanthoma elasticum (P.e.). This was done by comparing the above with normal skin under the electron microscope. The main difference is the increasing occurance of a fine granular-filamentous substance composed of microfibrils of varying thicknesses. A new formation arises as this substance is excreted by the activated fibroblasts and the combines extracellulary with the pathological elastic fibers. In the case of P.e. there is an additional calcification. It seems that with the elastogenesis of s.E. small elastic fibers are formed. P.e., in contrast, shows irregular electron-dense reticular sheets with numerous holes. The alteration of collagen observed in both diseases is considered as the primary change (which arises in both cases through the fine granular-filamentous material). In both diseases it is a matter of alterations of the little vessels, in endothel and basement membranes. We find here the same fine granular-filamentous substance in the elastic fibers of lamina interna, where as in P.e. we can see the calcification.