Reflectance confocal microscopy and dermoscopy for in vivo, non-invasive skin imaging of superficial basal cell carcinoma

Abstract

Superficial basal cell carcinoma (sBCC) is the second most frequent histological type of basal cell carcinoma (BCC), usually requiring a skin biopsy to confirm the diagnosis. It usually appears on the upper trunk and shoulders as erythematous and squamous lesions. Although it has a slow growth and seldom metastasizes, early diagnosis and management are of crucial importance in preventing local invasion and subsequent disfigurement. Dermoscopy is nowadays an indispensable tool for the dermatologist when evaluating skin tumors. Reflectance confocal microscopy (RCM) is a novel imaging technique that allows the non-invasive, in vivo quasi-microscopic morphological and dynamic assessment of superficial skin tumors. Moreover, it offers the advantage of performing infinite repeatable determinations to monitor disease progression and non-surgical treatment for sBCC. Herein, we present three lesions of sBCC evaluated using in vivo and non-invasive imaging techniques, emphasizing the usefulness of combining RCM with dermoscopy for increasing the diagnostic accuracy of sBCC.

Keywords: dermoscopy; in vivo skin imaging; non-invasive; reflectance confocal microscopy; superficial basal cell carcinoma.

Figure 1.

Lesion no. 1. (A) Clinical image showing a pink-colored patch with telangiectasias and ill-defined borders on a lentiginous background skin; (B) corresponding dermoscopic image with pink to red structureless areas, arborizing microvessels, short fine telangiectasias and few blue-gray globules; (C) histopathological image displaying a small island of basaloid cells with peripheral palisading that is connected in multiple places to the epidermis (Giemsa staining, ×10 magnification); (D) Reflectance confocal microscopy (RCM) image at the level of the stratum spinosum showing streaming of the epidermis (dashed white line); (E) RCM image just below the epidermis showing an island of elongated tumor cells with polarized nuclei forming the typical peripheral palisade (yellow asterisk), surrounded by highly refractile collagen bundles (green asterisk); (F) RCM image in the upper dermis revealing an inflammatory cell infiltrate (thin yellow arrow); (G) RCM image of a typical island of basaloid cells with peripheral palisading (yellow asterisk) and thin peritumoral dark spaces (thin green arrow). A dilated, horizontal capillary can be seen adiacent to the tumor island (short white arrow); (H) RCM image revealing aggregations of basaloid cells (yellow asterisks), surrounded by peritumoral, dark spaces (thin green arrow), connected into a multilobular, flower-like architecture by highly-reflactile, fibrous tissue (green asterisk).

Figure 2.

Lesion no. 2. (A) Clinical image of an erythematosquamous plaque with an irregular border; (B) corresponding dermoscopic appearance with pink-white structureless areas, small erosions, arborizing microvessels, superficial fine telangiectasias and brown dots; (C) Histopathological image displaying islands of basaloid cells with peripheral palisading that emanate from the undersurface of the epidermis (hematoxylin and eosin staining, ×10 magnification); (D) Reflectance confocal microscopy (RCM) image at the level of the stratum spinosum showing streaming of the epidermis (dashed white line); (E) RCM image revealing a lobulated tumor island (yellow asterisk) surrounded by peritumoral dark spaces (thin green arrow); (F) RCM image showing an erosion (red asterisk) and at its superior pole, entwined capillaries (short white arrow); (G) RCM image of bright inflammatory cells (thin yellow arrows); (H) RCM image at the level of upper dermis showing dark silhouettes (white asterisks), hyporefractile compared to the surrounding stroma, speckled with brightly refractile inflammatory cells (thin yellow arrows).

Figure 3.

Lesion no. 3. (A) Clinical image of an erythematous, slightly scaly plaque with a stelate shape; (B) dermoscopic image showing pink to red structureless areas, multiple arborizing microvessels, superficial fine telangiectasias and few brown dots; (C) histopathological examination reveals islands of basaloid cells in the papillary dermis, with characteristic peripheral palisading (hematoxylin and eosin staining, ×10 magnification); (D) Reflectance confocal microscopy (RCM) image of the dermis revealing tortuous, dilates capillaries (short white arrows); (E) RCM image at the level of upper dermis showing clusters of inflammatory (thin yellow arrows) and plump cells (thin white arrow); (F) RCM image of hyporefractile tumor islands (white asterisk) embedded by bright, fibrous stroma (green asterisk). Dichotomous capillaries can be seen in the upper and lower parts of the image (short white arrow); (G) RCM image of bright, plump cells (thin white arrows) within a tumor mass; (H) RCM image at the level of the upper dermis showing a tumor island (yellow asterisk) that is surrounded by highly-refractile collagen (green asterisk), tortuous, dilated capillaries (short white arrows), clustered inflammatory cells (thin yellow arrows) and a highly-refractile dendritic structure (thin red arrow).