p53 Immunostaining in Dermatopathology
Cristofolini et al1 describe p53 immunostaining in occasional benign melanocytic nevi and conclude that this observation greatly hinders the diagnostic use of p53 immunostaining in dermatopathology. This interpretation is in danger of missing the point. At best, p53 immuno-staining may be seen in approximately 50% of nonmelanoma skin cancers, including keratoacanthomas,2which renders it almost useless as a marker of the malignant phenotype. Even in melanoma, where a higher prevalence of p53 immunoreactivity has been reported in some studies,3,4 strong positive staining is predominantly seen in advanced lesions where the distinction between benign and malignant is not likely to be a problem. Surely we should not be considering p53 immunoreactivity as a diagnostic tool but as a potential marker of tumor behavior? Recent evidence suggests p53 positivity in certain malignancies is associated with poor patient survival, and in this respect it deserves our