Lichen simplex chronicus Vidal: comparative submicroscopic aspects of acanthotic disorders.

Electron microscopic analyses of lichen simplex chronicus Vidal (LSC) are reported. The submicroscopic organization is described. The frequent occurrence of collagen fibres directly juxtaposed to and contiguous with the lamina basalis seems to be a distinguishing feature of the LSC. Discontinuations in the lamina basalis are rarely indicated. A ubiquitous fragmentation and a certain paucity of tonofilamentous structure are present in cells preceding parakeratosis. There is an indubitable paucity of tonofilament-keratohyalin association. Mitochondria, endoplasmic reticulum and ribosomes are abundant. Odland bodies of type II are completely dominant. Parakeratosis and observed submicroscopically deficient or incomplete orthokeratosis are related to the numbers of defective Odland bodies. The keratinization of some acanthotic disorders is discussed.