The following is a summary of “Comparing Follicular Extension Between Low-Grade and High-Grade Dysplastic Nevi,” published in the June 2023 issue of Dermatopathology by Grube et al.
Dysplastic nevi are a significant subset of melanocytic nevi with atypical clinical, histopathologic, and genomic characteristics compared to typical acquired nevi. Histologically, dysplastic nevi are characterized by both cytologic atypia and architectural dysfunction. There is a shortage of objective, reproducible features of architectural disorder (e.g., pagetoid scatter) that have been validated to distinguish between low-grade and high-grade dysplastic nevi.
This study aimed to ascertain whether low-grade and high-grade dysplastic nevi differ in the presence and degree of follicular extension. Researchers retrospectively analyzed the histopathologic characteristics of 90 dysplastic nevi, including 60 cases of low-grade dysplastic nevi (average age: 47.2 18.1 years; 62.7% female) and 30 cases of high-grade dysplastic nevi (average age: 47.4 19.8 years; 60% female). 50% of the dysplastic nevi cases (n = 45) had hair follicles within the lesion, for which the presence and degree of follicular extension were determined.
The presence of follicular extension, the average depth of follicular extension, and the confluence of nevus cells along the follicular epithelium are not substantially different between low-grade and high-grade dysplastic nevi. In their study, low-grade and high-grade dysplastic nevi exhibited superficial follicular extension, that is, above the isthmus of hair follicles (sebaceous gland insertion into hair follicle). Future research is required to confirm these preliminary results.
