Basal cell carcinoma (BCC) and trichoepithelioma (TE) are common skin tumors that are characterized morphologically by proliferation of basaloid cells; however, TE is a benign tumor, whereas BCC is more aggressive. Differentiation between the two tumors is sometimes a diagnostic challenge for the pathologists. Moreover, some authors consider that BCC is less differentiated tumor, whereas TE a better differentiated follicular neoplasm. This is supported by the presence of follicular papillae in TE. Embryologically, the formation of perifollicular nerve plexus occurs later than the formation of the follicular papillae.Objective
The aim of work of this study was to examine the presence of perifollicular nerve plexuses in both tumors by using neurofilament (NF) immunohistochemistry, which may reflect the stage of differentiation of both these neoplasms.Material and methods
Twenty cases of BCC and 10 cases of TE were investigated for the presence of a peritumoral nerve plexuses using NF immunostaining. Immunohistochemistry for NF was carried out on sections obtained from formalin-fixed, paraffin-embedded blocks.Results
NFs protein immunoreactivity was documented in 16 out of the 20 cases of BCC (80%) compared with positivity in eight out of 10 cases (80%) of TE.Conclusion
The immunohistochemical demonstration of perifollicular nerve plexuses in both BCC and TE indicates that both tumors are terminally differentiated and their presence is not of great value in differentiating the tumors. The ability of infiltration of BCC may be due to causes other than the stage of differentiation.