High-frequency ultrasound: an essential non-invasive tool for the pre-therapeutic assessment of basal cell carcinoma

Abstract

Aim: While histology remains the "gold standard" for cutaneous tumoral pathology, high-frequency ultrasound (HFUS) was shown to play a significant role in the non-invasive, pre-therapeutic assessment of skin tumors. The aim of our study was to determine whether there is a significant correlation between the ultrasound (US) and histological measurements of basal cell carcinoma (BCC) tumor depth. Materials and Methods: The present study retrospectively analyzed clinical, dermoscopy, HFUS and histological examinations of 90 patients (52 men and 38 women) with histologically confirmed BCC, with focus on tumor depth index (DI). Results: On clinical examination, 54 lesions were nodular (32 presented ulcerations) and 36 superficial lesions. Dermoscopy showed suggestive signs of BCC, most frequently "in focus" arborising superficial vessels (n=81), blue-grey ovoid nests (n=48) and specks of brown pigment (n=7). HFUS revealed well-defined (n=88) or poorly defined (n=2) hypoechoic, vascularized lesions, with inhomogeneous structure (n=90) and characteristic hyperechoic dots (n=36). A strong correlation (Pearson's r=0.92) between the HFUS (mean measured US depth = 1.33 mm) and histological (mean measured histological depth = 1.47 mm) DI of the investigated skin lesions was found, although significant differences (p<0.001 -t-test for paired samples) between the two measurements were observed. Conclusions: HFUS provides reliable information about BCC depth of invasion that cannot be otherwise obtained prior to surgery. In this manner, it completes the preclinical evaluation and can have an impact on the choice of the optimal therapeutic method.

Top Advances in Dermatologic Ultrasound

“…BCCs commonly appear as oval-shaped hypoechoic dermal and/or deeper tumors with irregular borders and low to moderate vascularity with slow flow vessels (Figure 11). 1,[4][5][6][7][8]28,37,48,[68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85] Nevertheless, the morphology of these tumors may show asymmetric or hourglass shapes, among other patterns. 83 A key ultrasonographic feature of BCC is the presence of hyperechoic spots that supposedly correspond to compact nests of atypical cells and less frequently to calcifications or corneum cysts.…”

“…BCCs commonly appear as oval‐shaped hypoechoic dermal and/or deeper tumors with irregular borders and low to moderate vascularity with slow flow vessels (Figure 11). 1,4–8,28,37,48,68–85 Nevertheless, the morphology of these tumors may show asymmetric or hourglass shapes, among other patterns 83 …”

Morphological aspects of basal cell carcinoma vascularization

“…By determining the size of the tumor, US enables for customized surgical planning for BCC, and it can assist in monitoring early BCC recurrence [ 49 , 50 , 51 ]. Moreover, other morphological data such as tumor width, length and aspect can be identified on HFUS examinations and patients’ therapy can be impacted by this (e.g., if HFUS identifies a superficial BCC, therapies such as photodynamic therapy and cryotherapy can also be used) [ 45 , 47 , 48 , 52 ]. In a study by Desai et al, because of HFUS they had better therapy results with a clearance rate of 90% [ 52 ].…”

“…The shrinkage of tissue due to formalin fixation can determine smaller histological measurements in comparison to the US ones [ 45 ]. Gray scale examination also provides information about tumors appearance, and it can correlate with the histological variant [ 47 , 48 , 54 ]. Due to its non-invasive ability to detect lesions’ depth and dimensions, invasiveness, and vascularization patterns, US can be helpful in the selection of the ideal BCC treatment in an individualized manner, in monitoring non-invasive medical treatments [ 45 ] and in recurrence evaluations [ 49 , 50 , 51 ].…”

Dermoscopy, reflectance confocal microscopy, and high‐frequency ultrasound for the noninvasive diagnosis of morphea‐form basal cell carcinoma

“… 6 HFUS can provide reliable information about BCC, such as histopathological subtype differentiation, margin delineation, and tumor size assessment. 8 , 9 The recurrence risk of BCC can be assessed preliminary by quantifying the ultrasonographic examinations. 8 The presence of seven or more hyperechogenic spots within the lesion has been associated with histological subtypes with a high risk of recurrence.…”