Advancements in Basal Cell Carcinoma Diagnosis: Non-Invasive Imaging and Multimodal Approach

Abstract

(1) Background: The aim of this study was to correlate the diagnostic criteria described in dermatoscopy, ultrasonography (US), ex vivo confocal microscopy, and histology to the most common subtypes of basal cell carcinoma (BCC). (2) Methods: We conducted a prospective study including 46 BCC cases, which were analyzed with dermatoscopy using the Delta 30 dermatoscope and Vidix 4.0 videodermoscope, with US using a high-resolution 20 MHz linear probe, with confocal microscopy, along with histopathological analysis. (3) Results: This study categorized BCC by histological subtype, with nodular being the most common (84.8%) and various other subtypes represented. US measurements of tumor thickness correlated strongly with the histopathological depth of invasion index (DI). Dermatoscopy analysis revealed significant associations between specific features and BCC subtypes. The DI was directly related to arborized vessels but inversely related to short, fine telangiectasias, maple-leaf-like areas, and spoke-wheel areas. The presence of ulceration was directly related to the DI. Confocal microscopy images exhibited several characteristics, including fluorescence, nuclear crowding, peripheral palisading, clefting, increased nuclear-cytoplasmic (N/C) ratio, and a "cauliflower-like" appearance. (4) Conclusion: The advanced detection of BCC through imagistic techniques like dermatoscopy, confocal microscopy, and ultrasound improves the diagnosis and may offer valuable insights for treatment in the future by evaluating lesion characteristics.

Keywords: basal cell carcinoma; depth of invasion index; dermatoscopy; ex vivo confocal microscopy; ultrasonography.

Figure 1

Superficial basal cell carcinoma (BCC). Dermoscopy shows short, fine telangiectasias, maple-leaf-like areas, and white streaks (a). Ultrasonography (US) shows a hypoechoic lesion, imprecisely delimited, located at the level of the epidermis and papillary dermis, and without a Doppler signal (b). Ex vivo fluorescence confocal microscopy (FCM) shows clefting and peripheral palisading of the superficial tumoral nest (red square) (c).

Figure 2

Nodular, adenoid BCC. Dermoscopy shows arborized vessels, blue-grey ovoid nests, and shiny white-red structureless areas (a). US shows a hypoechoic, oval, well-defined lesion that reaches the level of the reticular dermis and that contains hyperechoic points (b). Doppler mode shows an increase in tumor and peripheral vascularity (c). FCM shows well-defined tumor islands, palisading, and clefting (d).

Figure 3

Ulcerated BCC. Dermoscopy shows arborized vessels, ulceration, multiple blue-grey globules, and shiny white-red structureless areas (a). US shows a hypoechoic lesion, imprecisely delimited, that reaches the level of the reticular dermis and contains hyperechoic points (b). Doppler mode shows an increase in tumor and peripheral vascularity (c). FCM shows well-defined tumor islands and a “cauliflower-like” appearance (d).

Figure 4

Nodular BCC. Dermoscopy shows arborized vessels and shiny white-red structureless areas (a). US shows a hypoechoic lesion, imprecisely delimited, that reaches the level of the reticular dermis (b) without a Doppler signal (c). FCM shows well-defined tumor islands and a palisading, clefting, and “cauliflower-like” appearance (d).

Figure 5

Micronodular, infiltrating BCC. Dermoscopy shows arborized vessels, ulceration, multiple blue-grey globules, and shiny white-red structureless areas (a). US shows a hypoechoic lesion, imprecisely delimited, that reaches the level of the reticular dermis and contains hyperechoic points (b). FCM shows small fluorescent tumoral nests with the presence of dense stroma and clefting. 4 (c).