title: Proliferating cell nuclear antigen immunostaining in keratoacanthoma and squamous cell carcinoma of the skin.
abstract: Proliferating cell nuclear antigen expression was used to seek differences between keratoacanthoma and squamous cell carcinoma of the skin. These lesions of the skin continue to provoke interest due to their different biological behaviour in spite of histologically similar appearances. The primary antibody, PC10 was used in a three stage avidin biotin peroxidase complex technique on section from 27 cases of KA, 15 of well, 16 of moderately- and 15 of poorly differentiated SCC. The distribution of positive cells was determined and then one thousand randomly chosen lesional epithelial nuclei were categorised for PCNA immunoreactivity and the results expressed as percentage of epithelial nuclei stained. Statistical analysis revealed a highly significant trend in increasing %PCNA with histological grade of skin lesion (P < 0.0001). Poorly differentiated, although not other grades of squamous cell carcinoma have a significantly higher proportion of PCNA labelled nuclei than keratoacanthoma. In addition, the distribution of PCNA positive nuclei in keratoacanthoma are usually peripheral contrasting with the more diffuse pattern seen in most cases of SCC. %PCNA alone was a more powerful predictor of histological subtype than distribution alone. PCNA immunohistochemistry not only provides additional information facilitating the differential diagnosis between keratoacanthoma and moderate or poorly differentiated squamous cell carcinoma but also underlines the perplexing similarity between keratoacanthoma and well differentiated squamous cell carcinoma.
authors.affiliation: Department of Pathology, University of Sheffield Medical School.
authors.forename: J A
authors.initials: JA
authors.lastname: Royds
authors.forename: T J
authors.initials: TJ
authors.lastname: Stephenson
authors.forename: P B
authors.initials: PB
authors.lastname: Silcocks
authors.forename: S S
authors.initials: SS
authors.lastname: Bleehen
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007636:Keratoacanthoma / Q000473:pathology*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*; D012871:Skin Diseases / Q000473:pathology*; D012878:Skin Neoplasms / Q000737:chemistry* / Q000473:pathology
chemical_list: D018809:Proliferating Cell Nuclear Antigen