Cytologic and DNA-cytometric examination of oral lesions in lichen planus.

Background: The aim of the present study was to evaluate the diagnostic value of exfoliative cytology (EC) and DNA image cytometry applied to oral lesions of lichen planus (LP; n = 56), in order to detect or exclude malignant transformation.

Methods: Brush and excisional biopsies were obtained from 56 patients. In cases of oral LP in which brush biopsies were suspicious for tumor cells, nuclear DNA contents were measured, using a TV Image Analysis System.

Results: In 50 patients EC yielded tumor cell-negative, doubtful in four cases and suspicious results obtained in two cases. DNA image cytometry revealed DNA-aneuploidy only in the two suspicious cases. The comparison between cytologic/DNA-cytometric diagnosis and biopsy histology resulted in a total agreement (LP without dysplasia: 54 and squamous cell carcinoma in LP: two cases).

Conclusions: In conclusion, cytology with DNA-cytometry is a highly sensitive, specific, and non-invasive method, which can be used for periodical follow up of oral LP lesions in order to early detect or exclude malignancy.