BACKGROUND AND DESIGN: Whether solitary keratoacanthoma (KA) is a malignant neoplasm despite its self-limited clinical behavior, and the distinction between KA and squamous cell carcinoma (SCC) are related aspects of a long-standing debate among dermatopathologists. Recent advances toward understanding the molecular basis of malignant transformation may allow this issue to be resolved. Mutant p53 tumor-suppressor protein has been shown to accumulate in cutaneous SCC and other tumors, and may be a relatively specific marker of malignancy. We studied 20SCCs, 20KAs, and an additional 10 regressing KAs (rKA) by immunohistochemistry for the expression of p53 protein. Since p53 is believed to play a pivotal role in the regulation of cell division, we also quantitated proliferation in the tumors by examining Ki-67 antigen expression. RESULTS: Sixteen (80%) of the KAs showed nuclear staining with anti-p53 antibody, distributed along the outermost layers of the aggregates of neoplastic cells, while 12 (60%) of the SCCs were p53 positive. Eight (80%) of the rKAs also showed p53 positivity. Mean Ki-67 proliferation fraction was higher for KA than for SCC (55% vs 46%), but this difference was not statistically significant. p53 Expression did not correlate with the grade of SCC. CONCLUSIONS: A majority of KA, rKA, and SCC contain stainable quantities of p53 protein, supporting the view that KA is a type of regressing SCC.
BACKGROUND AND DESIGN: Whether solitary keratoacanthoma (KA) is a malignant neoplasm despite its self-limited clinical behavior, and the distinction between KA and squamous cell carcinoma (SCC) are related aspects of a long-standing debate among dermatopathologists. Recent advances toward understanding the molecular basis of malignant transformation may allow this issue to be resolved. Mutant p53tumor-suppressor protein has been shown to accumulate in cutaneous SCC and other tumors, and may be a relatively specific marker of malignancy. We studied 20SCCs, 20KAs, and an additional 10 regressing KAs (rKA) by immunohistochemistry for the expression of p53 protein. Since p53 is believed to play a pivotal role in the regulation of cell division, we also quantitated proliferation in the tumors by examining Ki-67 antigen expression. RESULTS: Sixteen (80%) of the KAs showed nuclear staining with anti-p53 antibody, distributed along the outermost layers of the aggregates of neoplastic cells, while 12 (60%) of the SCCs were p53 positive. Eight (80%) of the rKAs also showed p53 positivity. Mean Ki-67 proliferation fraction was higher for KA than for SCC (55% vs 46%), but this difference was not statistically significant. p53 Expression did not correlate with the grade of SCC. CONCLUSIONS: A majority of KA, rKA, and SCC contain stainable quantities of p53 protein, supporting the view that KA is a type of regressing SCC.
Authors: Ole Petter F Clausen; Hans Christian D Aass; Marzieh Beigi; Karin J Purdie; Charlotte M Proby; Victoria L Brown; Morten Mattingsdal; Francesca Micci; Steen Kølvraa; Lars Bolund; Paula M Deangelis Journal: J Invest Dermatol Date: 2006-05-25 Impact factor: 8.551
Authors: Isabela C Watanabe; Renata F Magalhães; Aparecida M de Moraes; Rafael F Stelini; Geórgia F Cintra; Konradin Metze; Maria L Cintra Journal: Medicine (Baltimore) Date: 2015-06 Impact factor: 1.889