Bin Dong,1,* Hongsheng Xia,1,* Ying Liu,2 Hailiang Tao,1 Yan Xia,1 Feifei Zhu1 

1Department of Ultrasound, Hangzhou Third People’s Hospital, Hangzhou Third Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China; 2Cancer Center, Department of Ultrasound Medicine, Zhejiang Provincial People’s Hospital(Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Ying Liu, Cancer Center, Department of Ultrasound Medicine, Zhejiang Provincial People’s Hospital(Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, 310014, People’s Republic of China, Email sag1002@126.com

Background: 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.
Methods: 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.
Results: 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.
Conclusion: 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.

Keywords: dermatofibroma, very-high-frequency ultrasound, dermatosis