Send to

Choose Destination
See comment in PubMed Commons below
Arch Dermatol. 1994 Feb;130(2):181-6.

p53 oncoprotein expression and proliferation index in keratoacanthoma and squamous cell carcinoma.

Author information

Department of Pathology, University of California at San Francisco.



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.


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.


A majority of KA, rKA, and SCC contain stainable quantities of p53 protein, supporting the view that KA is a type of regressing SCC.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Silverchair Information Systems
    Loading ...
    Support Center