Characterization of dermatofibromas and epidermoid cysts using dermoscopy-guided high-frequency ultrasound imaging

Purpose Epidermoidcystsanddermatofibromasmayresemblemalignantlesions,requiringaccuratenon-invasivedifferentia- tion. Our objective was to assess dermoscopy-guided high-frequency ultrasound (DG-HFUS) in distinguishing these lesions. Methods Nine lesions (four epidermoid cysts, five dermatofibromas) were examined using DG-HFUS with a 33 MHz linear probe in B-mode. The dermoscopic modality guided probe placement. For each lesion, a minimum of 10 consecutive frames were acquired to ensure measurement reproducibility. Lesions were evaluated based on predetermined characteristics. Results Epidermoidcystspresentedaswell-circumscribed,ovallesionslocatedinthedermisordermal–subcutaneousborder, with depths of 1.4–8.7 mm. All showed mixed echogenicity with hyperechoic foci and bands. Dermatofibromas were smaller (2.4–3.5 mm), within the dermis, hypoechoic with scattered hyperechoic areas, poorly defined margins, and 3–5 hypoechoic bands extending into surrounding structures. Conclusion DG-HFUS reliably correlated dermoscopic and sonographic features, enhancing non-invasive diagnosis of benign cutaneous lesions.