CYTOLOGICAL AND CYTOCHEMICAL INVESTIGATIONS ON GRANULAR CELLS IN ORALLICHEN-PLANUS

Two biopsy specimens showed unusual histology characterized by feature s consistent with resolving oral lichen planus and voluminous, finely granular cells in the lamina propria, resembling the cells of granular cell tumour. Immunocytochemistry and lipid-pigment histochemistry ind icated that the granular cells are macrophages of low proliferative ac tivity laden with early ceroid. It is likely that damaged basal kerati nocytes provide debris for the formation of the latter. 'Oral ceroid g ranuloma' would be an appropriate term for collections of such reactiv e macrophages occurring in the oral tissues.