Evaluation of Very-High-Frequency Ultrasound Imaging Characteristics of Dermatofibroma

Dermatofibroma (DF) is one of the common dermatosis, which is so challenging to diagnose that its misdiagnostic incidence is quite high. The very-high-frequency (VHF) ultrasound is particularly relevant to the diagnosis of DF. Herein, we analyze the sonographic features and application value of VHF ultrasound in the diagnosis of DF.

Clinical data from 153 patients with pathologically confirmed DF from January 2019 to December 2023 were retrospectively analyzed using high-resolution VHF ultrasound, including size, location, shape, edge, boundary, interior echo, blood supply and so on.

The VHF sonographic features of DF showed that the maximum diameter of the lesions was about 7.29 ±2.85 mm (mean ± standard deviation). In addition, most lesions were located in the middle and lower part of dermis (49%), with ill-defined (84%) and irregular shape (51%), 19% of which were serrated. Forty-four percent of lesions were hypo-echoic and heterogeneous, and 8% were complicated with calcifications. Nineteen percent of lesions presented as thickened dermal epidermal junction. Dermatofibroma are mostly hypovascular on color Doppler ultrasound. Forty-three percent of lesions were detected with punctate dotted blood flow signals. The correlation analysis showed blood flow classification and maximum diameter were not relevant.

The DF based on VHF ultrasonographic findings is characteristic, such as <10mm, ill-defined, located in the dermis, thickened DEJ, serrated shape, punctute or no flow on Doppler, which provide crucial indicators for differential diagnosis, potentially reducing the rate of DF misdiagnosis.