title: Squamous cell carcinoma arising in keratoacanthoma: a neglected phenomenon in the elderly.
abstract: Keratoacanthoma is a unique clinicopathologic entity with a behavior and clinical outcome that differs markedly from that of squamous cell carcinoma. The development of squamous cell carcinoma in a keratoacanthoma alluded to by Rook and Whimster in 1979 and by Reed in 1993 was confirmed by Sánchez Yus et al in 2000. We found this phenomenon in 5.7% of keratoacanthomas in a series of 3465 cases. Its incidence in patients older than 90 years was 13.9%. The incidence of perineural invasion in this series of keratoacanthomas was 0.2%.
authors.affiliation: Sullivan Nicolaides Pathology, 134 Whitmore Street, Taringa, Queensland, Australia. d_weedon@snp.com.au
authors.forename: David D
authors.initials: DD
authors.lastname: Weedon
authors.forename: Jonathan
authors.initials: J
authors.lastname: Malo
authors.forename: David
authors.initials: D
authors.lastname: Brooks
authors.forename: Richard
authors.initials: R
authors.lastname: Williamson
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D006801:Humans; D015994:Incidence; D007636:Keratoacanthoma / Q000453:epidemiology* / Q000473:pathology*; D009361:Neoplasm Invasiveness; D010525:Peripheral Nerves / Q000473:pathology; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000473:pathology*