{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T13:07:14Z","timestamp":1775653634034,"version":"3.50.1"},"reference-count":46,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T00:00:00Z","timestamp":1775606400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dentistry Journal"],"abstract":"<jats:p>Objectives: This systematic review aimed to evaluate malignant transformation (MT) in extraoral lichen planus to help contextualize the debated malignant potential of oral lichen planus in a mucocutaneous disease model. Methods: A comprehensive literature search was conducted across five databases and gray literature sources, without date restrictions. Observational studies reporting MT in cutaneous or genital LP were included. Data extraction, risk of bias assessment using Joanna Briggs Institute (JBI), and meta-analysis of proportions were performed. Subgroup analyses by anatomical site were conducted where possible. Results: Ten studies (15,829 patients) were included, with a predominance of women (93.1%). The pooled MT rate of extraoral LP was 1% (95% CI: 0.00\u20130.03). Subgroup analysis revealed a significantly higher rate in vulvar LP (2%; 95% CI: 0.02\u20130.03) compared to cutaneous LP (0%; 95% CI: 0.00\u20130.01) (p &lt; 0.0001). Squamous cell carcinoma was the most frequent malignancy. The erosive and hypertrophic subtypes of LP were more commonly associated with cancer development. Conclusions: MT of extraoral LP appears to be rare, particularly in cutaneous forms. However, the risks observed in the genital mucosa reinforce the need for accurate diagnosis and long-term follow-up, especially in erosive presentations.<\/jats:p>","DOI":"10.3390\/dj14040217","type":"journal-article","created":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T11:41:18Z","timestamp":1775648478000},"page":"217","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Malignant Transformation in Extraoral Lichen Planus: A Systematic Review and Meta-Analysis in the Context of the Risk in Oral Lichen Planus"],"prefix":"10.3390","volume":"14","author":[{"given":"Ana Carolina Evangelista","family":"Colafemina","sequence":"first","affiliation":[{"name":"Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba 13414-903, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Caique Mariano","family":"Pedroso","sequence":"additional","affiliation":[{"name":"Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba 13414-903, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maria Eduarda","family":"Perez-de-Oliveira","sequence":"additional","affiliation":[{"name":"Department of Clinical and Preventive Dentistry, Universidade Federal de Pernambuco, Recife 50670-420, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0307-4991","authenticated-orcid":false,"given":"Ana Gabriela Costa","family":"Normando","sequence":"additional","affiliation":[{"name":"Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba 13414-903, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8787-9972","authenticated-orcid":false,"given":"Katherine","family":"France","sequence":"additional","affiliation":[{"name":"Department of Oral Medicine, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rafael Tomaz","family":"Gomes","sequence":"additional","affiliation":[{"name":"Private Practice, Sao Paulo 01000-000, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4472-365X","authenticated-orcid":false,"given":"Marcelo Henrique","family":"Napimoga","sequence":"additional","affiliation":[{"name":"Faculdade S\u00e3o Leopoldo Mandic, Instituto de Pesquisas S\u00e3o Leopoldo Mandic, Campinas 13045-755, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6677-0065","authenticated-orcid":false,"given":"Marcio Ajudarte","family":"Lopes","sequence":"additional","affiliation":[{"name":"Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba 13414-903, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2040-6617","authenticated-orcid":false,"given":"Alan Roger","family":"Santos-Silva","sequence":"additional","affiliation":[{"name":"Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba 13414-903, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Boch, K., Langan, E.A., Kridin, K., Zillikens, D., Ludwig, R.J., and Bieber, K. 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