Korean J Dermatol.  2021 Jun;59(5):341-347.

Clinico-Dermoscopic Features of Atypical Dermatofibroma

• Oh H
• Moon HR
• Ryu HJ
• Kim IH

Abstract

Background
Dermatofibroma is a common benign skin neoplasm that is usually easy to recognize; however, in some cases, it is difficult to differentiate it from atypical dermatofibroma. Atypical dermatofibroma is a rare variant of a more aggressive nature and requires complete excision due to its tendency to recur.
Objective
To describe the clinical and dermoscopic features of dermatofibromas with special emphasis on the characteristics of atypical subtypes and to differentiate them from typical subtypes on the basis of results.
Methods
We retrospectively searched the databases of patients of Korea University Ansan Hospital from January 2010 to December 2019 who underwent skin biopsies or excision surgeries and had pathological reports of dermatofibroma. Analyses of the clinical characteristics (age, sex, number of lesions, anatomical site) and dermoscopic patterns were performed.
Results
Dermoscopic patterns were analyzed in 148 cases of dermatofibroma; peripheral delicate pigment networks and central white scar-like patches were the most common patterns found in 45 cases (30.4%). In eight cases of atypical dermatofibroma, three cases (37.5%) showed peripheral homogenous areas and central white networks, followed by multiple white scar-like patches in 2 cases (25.0%), peripheral delicate pigment networks, and central white scar-like patches in 2 cases (25.0%). Dermoscopy revealed a statistically significant difference in the peripheral homogenous area and the central white network pattern between the two groups.
Conclusion
In this study, we analyzed the dermoscopic findings of 148 patients with dermatofibroma and found that the peripheral homogenous area and central white network patterns were significantly more in atypical dermatofibroma.

Keyword

Dermatofibroma; Dermoscopy