ABSTRACT
OBJECTIVES: Perineural invasion (PNI) is an important factor in tumor prognosis. We evaluated p75 nerve growth factor receptor (p75NGFR) as a neuromarker for perineural invasion of squamous cell carcinoma. METHODS: A comparison of H&E, and S100 and p75NGFR immunohistochemical staining methods, using sequential sections from 29 samples, for identification nerve bundles and PNI diagnosis, was carried out. RESULTS: p75NGFR and S100 correctly identified more nerve bundles than H&E. Accuracy of p75NGFR was higher than that of S100, but there was no significant difference from H&E. The accuracy of nerve bundle identification by p75NGFR and S100 showed no significant difference among different histopathologic grades of squamous cell carcinomas. p75NGFR gave mild staining of small vessels, while S100 gave strong staining of smooth muscle and glandular tissue. CONCLUSIONS: p75NGFR specifically stains nerve tissue and is better than S100 and H&E in identifying nerve bundles. p75NGFR is expected to become a new neuromarker.