Ber-EP4 is a highly sensitive immunohistochemical marker for cutaneous BCC, showing predominantly diffuse expression across diverse clinicohistologic contexts. However, reduced expression in ulcerated tumors and the presence of nondiffuse staining patterns highlight potential diagnostic pitfalls, particularly in superficially sampled lesions. These findings underscore the need for cautious interpretation and integrated histomorphological and immunohistochemical assessment to ensure diagnostic accuracy.
Tran et al. (2026) studied this question.