High-frequency (22-MHz) ultrasound for assessing the depth of basal cell carcinoma invasion.

Abstract

High-frequency ultrasound (HFUS) has been studied in the diagnosis and therapeutic management of basal cell carcinoma (BCC). The accuracy of this method for location of deep margins remains unknown. This study evaluates HFUS for localization of deep surgical margins in BCC. Ultrasound images of 83 lesions from 67 patients with clinical and dermoscopic diagnosis of BCC were compared with histopathological findings. Pearson's correlation coefficient was used to assess the relationship between thickness as measured by HFUS and histopathology. A strong correlation between HFUS and histopathological measurements was identified (r=0.9744, P<.001). HFUS had sensitivity of 96%, specificity of 84%, and accuracy of 91% for measurement of deep tumor margins. Factors affecting tumor measurement on HFUS include marked basophilic degeneration of collagen, presence of peritumoral hypertrophic glands or hair follicles, fibrosis, and dense inflammatory changes related to the tumor itself or to prior procedures. High-frequency ultrasound was effective in localizing deep tumor margins in BCC. Therefore, we believe that this diagnostic imaging method is important when selecting a therapeutic approach, considering Mohs micrographic surgery, and evaluating the surgical site.