de la Fouchardière A, et al. - In this investigation, researchers evaluated the nuclear β-catenin immunohistochemical expression in a large group of deep penetrating nevi (DPN) and in the four most frequent differential diagnoses of DPN: “blue” melanocytic tumors, Spitz tumors, nevoid and SSM melanomas, and pigmented epithelioid melanocytomas (PEM). According to findings, nuclear β-catenin expression in a dermal melanocytic tumor is an reason for classifying it as DPN, regardless of the expression of CCND1. Investigators found that this antibody can be valuable as a screening tool in uncertain cases and in early combined DPN lesions. In a subset of malignant melanomas with CTNNB1 mutations, β-catenin may also be expressed.