Ultrasound Features of Onychopapilloma at High-Frequency and Ultra-High Frequency

Objective: This study aimed to identify the sonographic features of pathologically confirmed onychopapilloma cases. Methods: High-frequency up to 24 MHz and ultra-high frequency-ultrasound up to 71 MHz examinations were performed and correlated with their clinical and pathologic presentations. Results: Twenty-two cases met the criteria. Clinical presentations revealed longitudinal erythronychia in 63.3% of cases. The ultrasound examinations identified a hypoechoic band in the nail bed (86.3%), nail plate abnormalities including upward displacement (68.2%) and thickening (68.1%), focal hyperechoic focal spots on the nail plate (50%) and irregularities of the ventral plate (33.3%). Color Doppler imaging showed no hypervascularity of the nail bed in all studies. These findings correlate with histological characteristics of onychopapilloma, including nail bed acanthosis, papillomatosis, and layered hyperkeratosis. Recurrence occurred in two cases after surgery, with tumors showing proximal extension in the matrix region on ultrasound not evident during clinical examination. Conclusion: High-frequency and ultra-high-frequency can provide anatomical information in onychopapilloma that could enhance understanding and management.