Immunohistochemical comparison of p63 and p40 in head and neck Spindle Cell Carcinoma

Spindle Cell Carcinoma (SpCC) is a rare type of squamous cell carcinoma (SCC) with prominent malignant spindle cell component. This unique biphasic feature on histopathological examination makes its diagnosis problematic. Detection of p63 antigens in SpCC can be helpful however its expression in variousb proliferating soft tissue lesions demands for better marker.

In this study, histopathologically diagnosed SpCC of head and neck region were considered as cases, and 22 soft tissue sarcomas, reactive lesions and spindle cell lesions of the body were taken as controls. Immunohistochemistry (IHC) was done using Anti-p63 and p40 clone and the results were compared. CK was done for negative cases to prove their epithelial origin. P. value < 0.05 considered statistically significant.

Among 22 cases of SpCC, 19 cases showed positive immunoreactivity to p63, and 18 cases for p40. IHC of controls showed no immunoreactivity in any of the sarcomas, reactive lesions or spindle cell lesions. The sensitivity of p63 is 86% while that of p40 is 82%. Specificity of both the markers was 100% CONCLUSION: Though p63 is a slightly (4%) more sensitive marker than p40, percentage of cell positivity for p40 is higher compared to p63. Both of these markers are 100% specific for SpCC.