High-Frequency Ultrasound and Shear Wave Elastography of Dermatofibrosarcoma Protuberans: A Novel Approach for Early Detection.

Objective: This study aimed to investigate the high-frequency ultrasound (HFUS) and shear wave elastography (SWE) features of dermatofibrosarcoma protuberans (DFSP) to enhance early diagnosis and improve clinical outcomes.

Methods: A retrospective cohort analysis was conducted with histopathologically confirmed DFSP, utilizing HFUS and SWE imaging data.

Results: Sixteen patients (10 males, 6 females; mean age 43 ± 11 years) with histopathologically confirmed DFSP were studied. The lesions were predominantly located on the trunk (56.25%), with a mean maximum diameter of 33.41 ± 16.17 mm and a maximum thickness of 14.49 ± 7.48 mm. Most lesions presented with elliptical (43.75%) or lobulated (37.50%) configurations. Sonographically, 81.75% showed a mixed hypoechoic-hyperechoic echo pattern with peripheral hyperechoic regions in 75% of cases. All lesions involved both dermal and subcutaneous tissue, with 43.75% showing finger-like projections. All lesions demonstrated vascularity on color Doppler, predominantly Grade 2 (62.5%). On SWE, the average Young's modulus was 38.68 ± 19.43 kPa, and 93.75% of lesions exhibited a characteristic "stiffer superficial cap" sign.

Conclusions: DFSP exhibits distinctive sonographic features including mixed echo patterns, peripheral hyperechoic regions, and finger-like projections. The newly identified "stiffer superficial cap" sign on SWE, combined with HFUS features, may improve the clinical suspicion of DFSP, potentially expediting biopsy decisions and definitive diagnosis.