A study on the expression of EZH2, Bcl-2 and Ber-EP in BCC

Basal cell carcinoma is the most common malignant tumour in humans. In cases with indistinct morphology on H&E-stained slides, immunohistochemistry may help distinguish basal cell carcinoma from other similar-appearing lesions. Our study aimed to investigate the expression of a marker panel comprising EZH2, Bcl-2, and Ber-EP4 in morphologically diagnosed, CK20-verified cutaneous basal cell carcinomas. Materials and methods: A cross-sectional study of 50 histologically confirmed cases of basal cell carcinoma was conducted. Immunohistochemical staining was performed using the following markers: EZH2, Bcl-2, Ber-EP4, and CK20. Due to the lack of a standardised method for evaluating markers, we adopted and modified the staining index (SI), which semi-quantitatively combines staining intensity and the percentage of positive cells. The results were systematised and interpreted using IBM SPSS. Results: All 50 examined tumours tested negative for CK20 (100%), thereby excluding mimics. All 50 tumours stained positive for EZH2 and Bcl-2 (100%), and only one stained negative for Ber-EP4 (98% positive). We found no association between histological type and EZH2 (p = 0.376), Bcl-2 (p = 0.376), and Ber-EP4 (p = 0.318), respectively, or their co-expression (p = 0.258). High co-expression of two of the three markers was observed in 33 of the 50 examined cases (66%), and a low co-expression in 4 cases (8%). Conclusion: The marker panel demonstrates co-expression of the three markers in the context of negative CK20 in over 90% of the cases. In challenging cases, it is important to consider clinical, morphological, and immunohistochemical features together.