Quantification of colloid bodies in oral lichen planus and oral lichenoid reaction - a histochemical study

Aim: Oral lichen planus and oral lichenoid reaction are familiar keratotic lesions found on the oral mucosa. Colloid bodies can be microscopically appreciated in both these lesions. The aim of this study was to identify as well as examine the frequency of colloid bodies in oral lichen planus and oral lichenoid reaction by histochemical means. Method: The material for the study included 12 formalin-fixed paraffin-embedded tissue blocks (7 oral lichen planus and 5 oral lichenoid reaction), retrieved from the Department of Oral Pathology and Microbiology, MCODS, Manipal. Sections stained with hematoxylin-eosin (H&E) and periodic acid-Schiff (PAS) with diastase to identify, locate and examine the frequency of colloid bodies in oral lichen planus and oral lichenoid reaction. Results: It was observed that the colloid bodies in case of oral lichen planus were present in either epithelium or connective tissue but usually close to the epithelium-connective tissue junction. While in oral lichenoid reaction colloid bodies were mostly seen in lower spinous layer of epithelium. Conclusion: Colloid bodies can be used as one of the criteria to differentiate oral lichen planus from oral lichenoid reaction. However, further studies are required to permit more objective distinction between oral lichen planus and oral lichenoid reaction.