Giant congenital melanocytic nevus of the scalp: from clinical-histological to molecular diagnosis

Abstract

Congenital melanocytic nevus (CMN) is a benign proliferative skin disease in the epidermis and dermis. Large to giant CMNs are estimated to be associated with an increased lifetime risk of malignancy. It is necessary to estimate and monitor the risk of malignant transformation for giant CMNs. To date, the clinical "ABCD" criteria and immunohistochemistry studies can be confusing and, to some extent, subjective. Accordingly, the elucidation of genomic analyses of nevi is required to better understand the malignant transformation of CMNs. Here, we describe two large to giant CMNs of the scalp with opposite clinical-histological and molecular evaluations of potential malignancy risk. To our knowledge, this is the first description of a genetic study of large to giant CMNs of the scalp in East Asia. We recommend reviewing the molecular diagnosis together with careful medical history and histological information to facilitate the evaluation of the potential malignancy risk.

A clinical and biologic review of congenital melanocytic nevi

“…As a disease caused by gene mutations, targeting abnormal cell proliferation and malignant transformation might be a promising strategy to help manage CMN, which could replace or further consolidate the effect of surgical intervention to a certain extent. 84 Research on targeted therapy for CMN has primarily concentrated on NRAS mutant samples. The direct inhibition of RAS has always been a challenge, as a result, an alternative approach that targets its downstream pathway is taken into consideration.…”

Cultured epithelial autografts for the treatment of large-to-giant congenital melanocytic nevus in 31 patients

“…Genetic abnormalities of large-to-giant CMN have been analyzed [ 4 , 5 ], and newly developed molecular-targeted drugs, such as MEK inhibitors, have been reported [ 6 ]. An important issue to note with GCMN is the risk of malignant transformation, the incidence of which is reported to be 0.7%–8.2% [ 2 , 7 , 8 ]; however, despite this risk, the full-thickness removal of GCMN is usually difficult due to a lack of skin for reconstruction, and the ideal medical treatment has not yet been established [ 5 , 9 ].…”