In vivo malignant transformation of cells from human oral lichen planus lesions.

When incubated in presence of patient's serum, but not normal serum, and complement, oral mucosa cells from patients with oral lichen planus (OLP) clumped together, the cell membrane was destroyed and the cells lysed. Whereas, cells from healthy volunteers maintained their morphology. Sixty to seventy days after inoculation into a thymic Nu/Nu BALB/c nude mice, cells from OLP lesions produced lesions in the recipient animals. Histological examination of these lesions showed hyperplasia with increased number of mitotic figures and dyskeratosis. These lesions resembled severe dysplasia and early squamous cell carcinoma.