Non-multiple medium-sized congenital melanocytic nevi: to excise or to follow up?

Introduction: Congenital melanocytic nevi (CMN) are benign lesions composed of clonal proliferations of melanocytes. Although medium-sized CMN are common and generally remain benign throughout a person's lifetime, they may be precursors of melanoma. There is a limited number of studies focused on the risk of melanoma in solitary, medium-sized, congenital melanocytic nevus; therefore, the incidence of malignant transformation and guidelines for treatment are not well established.

Aim: Prompted by the limited data, we conducted this study to gather more information about medium-sized CMN, to optimize clinical care. We share our analysis of surgically removed medium-sized CMN.

Material and methods: A total of 10 patients with non-multiple, medium-sized, congenital melanocytic nevus were included in this study. Lesions were removed using surgical procedures.

Results: In most of the cases the reason for excision of the medium-sized CMN was evolution of the lesion or aesthetic considerations reported by the patients. In 2 cases, due to the large size of the lesions, serial excisions were performed, while other CMN were removed surgically using simple excision technique. Eight of 10 medium-sized CMN were histologically described as benign, and 2 cases of malignant transformations were reported.

Conclusions: According to our clinical experience and knowledge, we recommend managing patients on an individual basis, taking into consideration multiple clinical attributes. In our opinion, long-lasting observation is the management of choice, and if there is need of surgery, we recommend total simple or staged excision depending on nevus size.