Apoptosis in lichen planus and several other dermatoses. Intra-epidermal cell death with filamentous degeneration.

In hyperplastic conditions of the skin, eosinophilic bodies are often observed in the epidermis and upper dermis. These have been named variously Civatte body of lichen planus and dyskeratotic cell of actinic keratosis. In the present studies, it was found that (i) these cells commonly contain whorls of distinct filaments (60-80 A), which may be attached to desmosomes; (ii) unlike keratinized cells, the cellular envelope was not thickened by the formation of the marginal band; (iii) the cytoplasm contains a large number of vacuoles; (iv) the nucleus is lost by condensation or diffuse disintegration; and (v) these cells could be dropped into the upper dermis and filamentous contents could be released to dermal phagocytes. From these observations it was concluded that Civatte bodies and other eosinophilic bodies of neoplastic and hyperplastic epidermis represent "filamentous degeneration" or premature keratinization of keratinocytes.