Dermoscopic Features of Calcinosis Cutis in 12 Dogs: An Observational Study

Background: Dermoscopy is a non-invasive technique used to preliminary assess skin lesions in humans and, more recently, in animals. Calcinosis cutis (CC) is an uncommon condition in dogs characterised by cutaneous calcification typically secondary to iatrogenic hyper-glucocorticism or endogenous hyper-adrenocorticism. Objectives: The aim of this study was to describe and characterise the dermoscopic features of CC in dogs affected by hyper-cortisolism, either iatrogenic or spontaneous, and assess the inter-observer agreement of the dermoscopic parameters. Materials and Methods: Twelve lesions from 12 client-owned dogs, histologically diagnosed as CC associated with spontaneous or iatrogenic hyper-cortisolism, were included in this study. Dermoscopic images of the lesions at ×10 magnification were independently evaluated on a computer screen by three ECVD board-certified veterinary specialists and one ECVD resident. Results: At ×10 magnification, all lesions exhibited single or multiple structureless bright white areas and erythema. In eight of the 12 lesions, these white areas surrounded prominent plugs of yellowish-to-brown material emerging from follicular ostia and/or epidermal ulcerations. The main vascular pattern was dominated by a single vessel type (monomorphic pattern), consisting mainly of short, dilated, linear curved vessels (seven of 12), with short linear vessels observed in four lesions. Histopathological results confirmed that the white structures observed dermoscopically corresponded to calcium deposits within the dermis. A specific association was not observed between dermoscopic features and the distribution or localisation of mineralisation described in the histological evaluations. Conclusions and Clinical Relevance: Dermoscopy represents a useful technique to assess CC in dogs.