title: Red, scaly spot with a central horn.
authors.affiliation: University of Arizona Health Sciences Center, Tucson, USA.
authors.forename: N
authors.initials: N
authors.lastname: Levine
mesh_terms: D000368:Aged; D001706:Biopsy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007642:Keratosis / Q000209:etiology / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*; D013472:Sunlight / Q000009:adverse effects