报告外阴硬化性苔藓（VLS）恶变的患病率和可能的危险因素。这是一项队列研究，对在大学医院外阴病理门诊登记的 138 例组织学诊断为 VLS 的患者的医疗记录进行数据分析。 2007 年至 2017 年间。使用逻辑回归分析对主要危险因素进行分析。研究的变量包括随访时间、年龄、定期或不定期随访；存在症状（性交困难、瘙痒和/或外阴灼烧感）；组织学特征，上皮增生的存在；该研究共纳入 138 名患者，其中 5 名进展为恶变。患者的中位年龄为 59 岁，83% 有症状。最常见的症状是瘙痒，占 72%。自身免疫性疾病占 11.6%，其中最常见的是甲状腺疾病。所有5例恶变病例（0.6%）均未定期随访。研究变量之间采用logistic回归分析，各变量间无统计学意义（p≥0.05）。增生与恶变临床结果之间的关系，观察到不显着但可接受的 p 值接近 0.05。VLS 患者恶变的发生率为 0.6%，常见因素是缺乏医疗依从性治疗和失去随访。

To report the prevalence of malignant transformation of vulvar lichen sclerosus (VLS) and possible risk factors.This is a cohort study with data analysis from medical records of 138 patients with histological diagnosis of VLS registered at the Vulvar Pathology Outpatient Clinic of the University Hospital, between 2007 and 2017. Predominance of risk factors was performed using logistic regression analysis. The variables studied were the length of follow-up, age, regular or irregular follow up; presence of symptoms (dyspareunia, pruritus and/or vulvar burning); histology characteristics, the presence of epithelial hyperplasia; and the presence of autoimmune diseases.There were 138 patients included in the study, and among them five progressed to malignant transformation. The patients had a median age of 59 years and 83% were symptomatic. The most frequent symptom was itching with 72%. Autoimmune diseases were present in 11.6%, the most prevalent being thyroid disease. All five case of malignant transformation (0.6%) had an irregular follow up. The logistic regression analysis was used among the studied variables, and no statistical significance was found among them (p ≥ 0.05). The relationship between hyperplasia and the clinical outcome of malignant transformation, in which non-significant but acceptable p value close to 0.05 was observed.The prevalence of malignant transformation in patients with VLS was 0.6%, and common factors were the lack of adherence to medical treatments and the loss of follow-up.