Proposal of a new dermoscopic criterion for pigmented basal cell carcinoma: a multicentre retrospective study

Abstract

Dermoscopy is widely used for the diagnosis of skin cancers and it increases the accuracy of basal cell carcinoma (BCC) detection. The dermoscopic criteria of BCC have recently been updated and they can be divided into three categories: vascular, pigment-related, and nonvascular/nonpigmentrelated. The objective of our multicentre retrospective study was to report the validity of a new dermoscopic pigment-related feature utilized to detect pigmented BCC (pBCC) (i.e., brown homogeneous blotches (BHB)). Cases of pBCC were collected from the databases of IDI-IRCCS of Rome and from three Italian private dermatology centres. BHB were defined as the presence of circumscribed areas of brown homogeneous pigmentation which are devoid of any dermoscopic specific arrangement (net, fat fingers, etc.) and of other internal dermoscopic structures, except for occasional vascular ones, such as arborizing vessels or globules/dots. Controls included melanocytic and non-melanocytic lesions. We examined images of 270 pigmented lesions (female 145; 51.8%) including 90 histopathological proven pBCC and 180 control cases (i.e., 90 melanocytic and 90 non-melanocytic lesions). BHB were present in 61 cases of 90 pBCC. These results showed a sensibility of 67.8 and a specificity of 93.3 with a positive predictive value of 83.6, negative predictive value of 85.3, posLR 10.2, negLR 0.3; OR 29.4, P value<0.001. Our multicentre retrospective study showed that the BHB may represent a new dermoscopic criterion for the diagnosis of pBCC.