Juvenile melanocytic acral nevus: A comparative study between MANIAC and non-MANIAC nevus and its clinicopathological characteristics.

ABSTRACT

BACKGROUND: Melanocytic acral nevi have a series of distinguishing features, including their location, patient age at onset, clinical progression, and histological findings. In particular, histopathological analysis often reveals a melanocytic acral nevus with intraepidermal ascent of cells (MANIAC nevus), which in some cases can be mistaken for atypia or malignancy. AIM: This study describes the clinicopathological characteristics of acral nevi in patients under 18 years old and contrasts the clinical and histological features between MANIAC vs non-MANIAC nevi. METHODS: This was a retrospective observational study, performed in our department in the decade between January 2007 and January 2017. We included patients younger than 18 years of age who were subjected to the removal of melanocytic acral nevi. RESULTS: A total of 70 patients were studied. 54.2% (38/70) were females and 45.8% (32/70) were males. With regard to the type of nevus, 34 were compound, 27 were junctional, and 9 were predominantly intradermal lesions. We identified a total of 41 MANIAC nevi and 29 non-MANIAC nevi. Statistically significant differences between these two groups were identified in nevus size (larger in MANIAC) and the frequency of compound nevi (higher in the MANIAC group), but not in the remainder of the histological parameters studied.