Light and electron microscopic studies of colloid bodies in lichen planus

The nature of Civatte bodies in oral lichen planus lesions of 11 patients was investigated by light and electron microscopy. The results suggested that these bodies were derived from keratinizing epithelial cells which formed discrete masses of tonofilaments. These masses appeared to be engulfed by cells containing structures morphologically similar to premelanosomes, melanosomes and melanin granules of the elongated and rounded types. Degenerating mast cells may also contribute to the formation of eosinophilic masses, but these may be distinguished from the previous type by the presence of metachromatic granules.