title: Lichenoid tissue reaction in malignant melanoma: a potential diagnostic pitfall.
abstract: Lichenoid tissue reactions can occur in malignant melanoma and may cause partial regression of the lesion. We studied a series of melanomas to determine how frequently lichenoid tissue reaction obscures the diagnosis of malignant melanoma. We retrospectively reviewed 342 cases of invasive malignant melanoma and melanoma in situ from the head, neck, chest, and back. Of the 342 cases, 23 (6.7%) had a lichenoid tissue reaction obscuring a portion of the lesion. In 6 cases (1.8%), the lichenoid tissue reaction replaced a major portion of the lesion. Knowledge of this phenomenon can prevent misdiagnosis.
authors.affiliation: Department of Pathology, Brooke Army Medical Center, Ft Sam Houston, TX 78234-3600, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Dalton
authors.forename: Matt A
authors.initials: MA
authors.lastname: Baptista
authors.forename: Lester F
authors.initials: LF
authors.lastname: Libow
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Elston
mesh_terms: D003951:Diagnostic Errors; D006098:Granulocytes; D006801:Humans; D007519:Isoantigens / Q000378:metabolism; D008010:Lichen Planus / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D008545:Melanoma / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000378:metabolism; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D007519:Isoantigens