Immunohistochemical Study of Cytokeratin Related Protein Expression in Patients with Trichilemmal Tumors and Squamous Cell Carcinoma of the Skin

Trichilemmal tumors can be either benign and malignant skin tumors arising from the outer root sheath of the hair follicle. It remains unknown whether malignant trichilemmal tumors can be differentiated from squamous cell carcinoma (SCC). In order to differentiate malignant trichilemmal tumors from SCC, we studied cytokeratin-related protein and involucrin expression immunohistochemically. Twenty-three trichilemmal carcinomas (TLC), 4 malignant proliferating tricholemmal tumors (MPTT) and 25 SCCs were studied. All the skin biopsy specimens were subjected to staining with anti-cytokeratin and anti-involucrin antibodies immunohistochemically, and the expression of cytokeratins and involucrin were investigated. The occurrence rate of cytoketatin 1 positive staining in TLC was significantly less than that in SCC (P<0.05), while that of cytokeratin 19 positivity in SCC was significantly less than that in TLC (P