Granular cells in oral lichen planus.

OBJECTIVE AND

DESIGN

Three cases of granular cells associated with oral lichen planus (OLP) have been reported to date, which prompted us to look for the presence of granular cells in a consecutive series of 250 cases of OLP in the period 1996-1998.

RESULTS

Only one case with granular cell changes was encountered in that series. H&E stained slides as well as direct immunofluorescence examination showed characteristics compatible with OLP. Part of the subepithelial connective tissue was replaced by a granular cell proliferation; S-100 protein was diffusely expressed in all granular cells, whereas no expression of smooth muscle actin was observed.

CONCLUSION

Based on these findings it seems unlikely that the granular cells in the present case represent a so-called 'oral ceroid granuloma'. The presence of granular cells might rather have been a reactive phenomenon triggered by the inflammatory infiltrate or a granular cell tumour (GCT). Whether the simultaneous presence of a GCT and OLP in this particular case was based on a causal relationship or on coincidence still remains unknown.