Inner gray halo, a novel dermoscopic feature for the diagnosis of pigmented actinic keratosis: Clues for the differential diagnosis with lentigo maligna

Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis

“…In line with previous studies, dermoscopy showed a significantly higher accuracy in the diagnosis of PFL compared with the unaided eye . The overall frequencies of criteria in LM and PAK in our study appear similar to those in previous reports, including both the ‘traditional’ pigmented criteria and the most recently described vascular structures of LM . In contrast, there is a discrepancy between our and previous studies concerning the dermoscopic criteria of SL/SK, which exhibited grey colour in about half of our cases, while grey colour has been suggested to represent the single most important clue for the diagnosis of LM.…”

“…The investigators were asked to assess the presence of predefined clinical and dermoscopic criteria. The selection of dermoscopic criteria was based on the available literature . Furthermore, we added into the dermoscopic evaluation a new criterion, which we named ‘evident follicles’.…”

“…This is because early facial melanoma (lentigo maligna type, LM), pigmented actinic keratosis (PAK) and solar lentigo/early seborrhoeic keratosis (SL/SK) may show overlapping morphological features . Even though significant progress has been made in differentiating LM from SL/SK by means of dermoscopy, its differentiation from PAK still remains troublesome …”

“…1,2 Even though significant progress has been made in differentiating LM from SL/SK by means of dermoscopy, its differentiation from PAK still remains troublesome. [3][4][5][6][7][8][9][10][11][12] The current limitations of dermoscopy in accurately differentiating PFL may be explained by the fact that most dermoscopic studies have focused their attention on well-known pigmented structures, instead of evaluating possible additional novel features. In fact, pigmented criteria such as grey colour, grey circles, grey rhomboidal lines (rhomboidal structures), grey dots (annular granular structures) and brown globules are well documented, but appear insufficient to differentiate LM from PAK, because they can be observed in both entities.…”

Dermoscopic and Reflectance Confocal Microscopy Findings in Extra-genital HPV16-associated Pigmented Squamous Cell Carcinoma in situ

“…For this reason, we assume that the abundance of melanin within the epidermis is probably due to activation of melanocytes, which can be observed through RCM in pigmented actinic keratosis, resulting in small bright polygonal keratinocytes surrounding the follicular opening (15).…”