[Scanning electron microscopy of the vestibular surface of the stapes in otospongiosis].

The authors, going on with their investigations of the otospongiotic micro-foci by means of scanning electron microscopy method, state their discoveries concerning the micro-foci of the footplates vestibular side, left aside too often up to now. On this vestibular side of the footplate, they have managed to find much more numerous pathological alterations than usually admitted. There are three types of lesions: 1. Strongly cellular micro-foci, most of them composed of histiocytes. 2. Fibrous micro-foci, containing numerous fibroblasts and looking like otospongiotic micro-foci of osteoid lamellae overhanging the tympanic side of the footplate and grasping it in the way of a lobster-claw. 3. A small number of scattered microlesions, having no relation with the two previous types, and seeming due to numerous initial otospongiotic micro-foci originated from one or several cells with altered metabolism on the footplate' side itself. The localization of these micro-foci of the footplate's vestibular side is extremely interesting for the knowledge of the otospongiotic disease, because they are in direct contact with the vestibule. They can thus spread their hydrolytic enzymes into the labyrinthine fluids as well as the otospongiotic micro-foci of the lateral wall which have been described by the authors in numerous papers.