IN VIVO REFLECTANCE CONFOCAL MICROSCOPY OF SPOKE-WHEEL STRUCTURES IN A PIGMENTED BASAL CELL CARCINOMA. CASE REPORT.

The "Consensus net meeting on dermatoscopy" of 2000 determined a set of significant dermatoscopic features for the diagnosis of pigmented basal cell carcinoma (pBCC). These included small ulcerations, maple leaf-like areas, multiple blue-grey globules, large blue-grey ovoid nests, arborizing telangiectasia, and spoke-wheel structures. The latter have been defined as brown to gray, well circumscribed, radial projections meeting at a darker brown central hub. Spoke-wheel structures have a reported specificity of 100% for pBCC. Because the correlation between dermatoscopy and histology is often difficult owing to the different incidences from which lesions are seen (horizontal in dermatoscopy vs vertical in histology), in this paper we sought to highlight the underpinnings of this particular dermatoscopic feature through in vivo reflectance confocal microscopy (RCM) examination. RCM is a non-invasive imaging technique capable of delivering images of en face optical sections at nearly histological resolution, thus facilitating the correlation with dermatoscopy. RCM examination of a pBCC exhibiting spoke-wheel structures revealed flower-shaped bright tumor islands infiltrated by dendritic cells, surrounded by dark areas of clefting at the level of the dermal-epidermal junction and papillary dermis. These tumor islands were connected to the epidermis through several cord-like projections. [ABSTRACT FROM AUTHOR]