title: Squamous Cell Carcinoma Arising in Hypertrophic Lichen Planus: A Review and Analysis of 38 Cases.
abstract: BACKGROUND
  Hypertrophic lichen planus is a chronic variant of lichen planus with controversial malignant association.
  
  
  OBJECTIVE
  To describe and analyze the relationship of squamous cell carcinoma (SCC) and hypertrophic lichen planus.
  
  
  METHODS
  A retrospective chart review of patients with hypertrophic lichen planus and SCC was performed at the authors' institution. Thereafter, scientific databases were searched for articles reporting cases of SCC arising in hypertrophic lichen planus. Patient demographics, immune status, lichen planus features, and SCC data points were extracted for each patient and evaluated.
  
  
  RESULTS
  Thirty-eight cases of SCC in hypertrophic lichen planus occurred in 16 women, average age: 61.4, and 22 men, average age: 51.3, after a lag time of 88 days to 40 years. Squamous cell carcinoma was uniformly located on the lower extremity. Men had larger SCC than women (p = .027) and a significantly longer lag time to SCC development (p = .002). Long lag time was associated with a smaller SCC size (p = .032).
  
  
  CONCLUSIONS
  In the past, hypertrophic lichen planus and SCC have been considered isolated diseases. Based on an increasing number of cases, the association between hypertrophic lichen planus and keratinocyte malignancies warrants surveillance.
authors.affiliation: *Department of Surgery (Section of Dermatology), Dartmouth-Hitchcock Medical Center, Lebanon, NH; †Biostatistics Shared Resource, Norris Cotton Cancer Center, Dartmouth College, Lebanon, NH; ‡Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH; §Geisel School of Medicine, Dartmouth College, Hanover, NH.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Knackstedt
authors.forename: Lindsey K
authors.initials: LK
authors.lastname: Collins
authors.forename: Zhongze
authors.initials: Z
authors.lastname: Li
authors.forename: Shaofeng
authors.initials: S
authors.lastname: Yan
authors.forename: Faramarz H
authors.initials: FH
authors.lastname: Samie
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D006984:Hypertrophy; D008010:Lichen Planus / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery; D013997:Time Factors