ORIGINAL ARTICLE Clinical and dermoscopic clues to differentiate pigmented nail bands: an International Dermoscopy Society study E. Benati, 1 S. Ribero, 2 C. Longo, 1 * S. Piana, 3 S. Puig, 4,5 C. Carrera, 6 F. Cicero, 7 H. Kittler, 7 T. Deinlein, 8 I. Zalaudek, 8 W. Stolz, 9 A. Scope, 10 G. Pellacani, 11 E. Moscarella, 1 B.M. Piraccini, 12 M. Starace, 12 G. Argenziano 13 1 Skin Cancer Unit, Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia, Italy 2 Section of Dermatology, Department of Medical Sciences, University of Turin, Turin, Italy 3 Pathology Unit, Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia, Italy 4 Melanoma Unit, Dermatology and Pathology Departments, Hospital Cl ınic Barcelona, Universitat de Barcelona, Barcelona, Spain 5 CIBER of Rare Diseases, Instituto de Salud Carlos III, Barcelona, Spain 6 Melanoma Unit, Dermatology and Pathology Departments, Hospital Cl ınic Barcelona, Universitat de Barcelona, Barcelona, Spain 7 Department of Dermatology, Division of General Dermatology, Medical University of Vienna, Vienna, Austria 8 Non-Melanoma Skin Cancer Unit, Department of Dermatology and Venerology, Medical University of Graz, Graz, Austria 9 Clinic for Dermatology, Allergology, and Environmental Medicine, Klinik Thalkirchner Straße Stadt, Klinikum Munchen GmbH, Munich, Germany 10 Department of Dermatology, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel 11 Department of Dermatology, University of Modena, Reggio Emilia, Italy 12 Division of Dermatology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy 13 Dermatology Unit, Second University of Naples, Naples, Italy *Correspondence: C. Longo. E-mail: longo.caterina@gmail.com Abstract Background Longitudinal melanonychia might be difcult to differentiate and the use of dermoscopy can be useful for the preoperative evaluation and management decision. Objectives The aim of our study was to investigate clinical and dermoscopic criteria of acquired longitudinal melanonychia in adults to identify the best predictors of melanoma using a multivariate analysis and to explore eventual new dermoscopic criteria for nail melanoma diagnosis. Methods In this retrospective observational study, 82 histopathologically diagnosed, acquired nail pigmented bands were collected and examined. All variables were included in the analysis and examined as possible predictors of nail mel- anoma. Both univariate and multivariable analyses have been performed. Results Among 82 cases, 25 were diagnosed as nail melanoma and 57 as benign lesions (including 32 melanocytic nevi and 25 benign melanocytic hyperplasia). Melanoma cases were signicantly associated with a width of the pig- mented band higher than 2/3 of the nail plate, grey and black colours, irregularly pigmented lines, Hutchinson and micro- Hutchinson signs, and nail dystrophy. Granular pigmentation, a newly dened dermoscopic criterion, was found in 40% of melanomas and only in 3.51% of benign lesions. Conclusions Dermoscopic examination of longitudinal melanonychia provides useful information that could help clini- cians to improve melanoma recognition. Received: 5 July 2016; Accepted: 19 September 2016 Conicts of interest None declared. Funding sources None declared. Introduction Longitudinal melanonychia is a brown to black pigmented band that extends from the proximal nail fold to the distal end of the nail plate. It may occur due to activation or benign and malignant proliferation of melanocytes of the nail matrix. 1,2 These entities may share clinical and dermoscopic features making sometimes difficult to discriminate between benign © 2016 European Academy of Dermatology and Venereology JEADV 2017, 31, 732736 DOI: 10.1111/jdv.13991 JEADV