Clinicopathologic features and treatment outcomes of marginal gingival (ring around the collar) leukoplakia: a systematic review of emerging evidence.

Marginal gingival leukoplakia, often referred to as ring around the collar leukoplakia, appears to have unique features compared with other leukoplakias, including higher rates of recurrence and malignant transformation. However, this type remains poorly described in the scientific literature. Therefore, this systematic review aimed to describe the clinicopathologic characteristics and treatment outcomes of marginal gingival leukoplakia. This review, which followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, included searches in major databases and the gray literature. The methodologic quality (risk of bias) of each included study was assessed with the appropriate JBI (Joanna Briggs Institute) checklist. The search identified 17 studies matching the inclusion criteria. The studies included in the analyses comprised a total of 66 patients (39 women and 27 men) with a mean age of 60 years. Lesions were predominantly homogenous (30.3%) and often involved adjacent teeth (66.7%). Proliferative verrucous leukoplakia was diagnosed in 33.3% of the patients. Treatments included scalpel excision (74.2%) and laser excision (15.1%), with recurrence in 45.4% of cases and malignant transformation in 24.2%. Histopathologically, hyperkeratosis was the most common feature (48.1%), and mild epithelial dysplasia was present in 21.2% of lesions. Marginal gingival leukoplakia is relatively uncommon and might belong to the proliferative verrucous leukoplakia spectrum. High recurrence rates and a considerable risk of malignant transformation highlight the need for individualized treatment plans. Further research is necessary to improve the understanding and management of this condition. PROSPERO registration: CRD42023440004.