Cryogun cryotherapy for oral leukoplakia and adjacent melanosis lesions

Background: Our previous study has shown that cryogun cryotherapy is a good and effective treatment modality for oral leukoplakia. Methods: In this study, we used cryogun cryotherapy to treat 72 oral leukoplakia and adjacent smoking-induced melanosis (OLM) lesions on the buccal mucosae. Results: Of 72 OLM lesions, 14 had epithelial hyperplasia with parakeratosis, 24 had epithelial hyperplasia with hyperkeratosis, 26 had mild dysplasia, seven had moderate dysplasia, and one had severe dysplasia. Complete regression was achieved in all 72 OLM lesions after a mean of 3.3 ± 1.3 cryogun cryotherapy treatments. We found that OLM lesions in patients without smoking habit, with the greatest diameter < 2.8 cm, with epithelial dysplasia, or with a surface keratin thickness ≤ 50 μm needed significantly fewer mean number of cryogun cryotherapy treatment to achieve complete regression than those OLM lesions in patients with smoking habit, with the greatest diameter ≥ 2.8 cm, without epithelial dysplasia, or with a surface keratin thickness > 50 μm (all P-values < 0.001), respectively. Univariate logistic regression analyses showed that the greatest diameter, epithelial dysplasia, smoking habit, and surface keratin thickness were the factors influencing the cryogun cryotherapy treatment number (all P-values < 0.001). However, only the greatest diameter < 2.8 cm (P < 0.001) was an independent factor influencing the number of cryogun cryotherapy treatment required to achieve complete regression of the OLM lesion by multivariate logistic regression analyses. Conclusion: Cryogun cryotherapy is an effective treatment modality for OLM lesions.