CLINICAL AND LABORATORY INVESTIGATIONS BJD British Journal of Dermatology Multiple primary melanomas: do they look the same? E. Moscarella, 1,2 H. Rabinovitz, 3 S. Puig, 4,5 I. Zalaudek, 6 M.C. Oliviero, 3 L. Brown, 3 I. Alarcon, 4 J. Malvehy, 4,5 C. Longo, 2 D. Formisano, 7 C. Carrera, 4,5 C. Badenas, 5,8 S. Piana, 2 G. Albertini, 2 G. Pellacani 1 and G. Argenziano 2 1 Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy 2 Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova IRCCS, Reggio Emilia, Italy 3 Skin and Cancer Associates, Plantation, FL, U.S.A. 4 Department of Dermatology, Melanoma Unit, Hospital Clı ´nic de Barcelona, IDIBAPS, Barcelona, Spain 5 Centre of Biomedical Research on Rare Diseases (CIBERER), ISCIII, Barcelona, Spain 6 Department of Dermatology, Medical University of Graz, Graz, Austria 7 Scientific Directorate, Arcispedale Santa Maria Nuova IRCCS, Reggio Emilia, Italy 8 Department of Biochemistry and Molecular Genetics Service, Melanoma Unit, Hospital Clı ´nic de Barcelona, IDIBAPS, Barcelona, Spain Correspondence Iris Zalaudek. E-mail: iris.zalaudek@gmail.com Accepted for publication 22 January 2013 Funding sources This study was supported in part by the Italian Ministry of Health (RF-2010-2316524). This work was partially developed in the Melanoma Units of Hospital Clinic I Provincial de Barcelona, IDIBAPS, partially supported by Fondo de Investigaciones Sanitarias (FIS grants 05 ⁄ 0302, 06 ⁄ 0265 and 09 ⁄ 1393) and by the GenoMEL fund of the European Commission under the 6th Framework Programme. Conflicts of interest None declared. DOI 10.1111/bjd.12260 Summary Background A series of studies has investigated epidemiological, clinical and genetic characteristics of patients with multiple primary melanoma (MPM). However, comparison of the clinical and dermoscopic features of MPM within a given indi- vidual has been described only in case reports. Objectives To describe the dermoscopic features of MPM for each given patient, and to evaluate the characteristics eventually associated with similar or dissimilar appearance. Methods From the databases of three skin-lesion clinics in the U.S.A., Italy and Spain we collected the dermoscopic images of melanomas in patients diagnosed with MPM. Results Among 58 patients with MPM, we found that 53% of patients had dermo- scopically similar melanomas and 47% of patients had dermoscopically different melanomas. In older patients 59% of melanomas were dermoscopically similar vs. 47% in younger patients (P =0Æ377). Similar thickness was associated with the occurrence of dermoscopically similar melanomas (19 ⁄ 30 cases, 63%; P =0Æ039). Most (65%) of the synchronous lesions were similar, compared with 36% of nonsynchronous lesions (P =0Æ029), and most (69%) of the melanomas on sun-damaged skin were similar, vs. 37% of melanomas on nonsun-damaged skin (P =0Æ015; odds ratio 3Æ88, 95% confidence interval 1Æ11–13Æ98). The per- centage of dermoscopically different melanomas was higher in patients with a family history of melanoma (67% vs. 48%). Conclusions MPMs in a given patient have almost the same chance of looking dermoscopically similar or different. However, a subset of elderly patients with sun-damaged skin may present multiple, similar, thin melanomas characterized by pigment-network and regression structures. The occurrence of multiple primary melanomas (MPMs) is a well-documented phenomenon. A number of studies have demonstrated that in patients with melanoma the risk of developing an additional primary tumour ranges from 1Æ3% to 8Æ0%. 1–5 Furthermore, it has been demonstrated that subse- quent primary melanomas are significantly thinner than index lesions, possibly due to increased surveillance. 6–11 These find- ings support the necessity of long-term follow-up of patients with a history of melanoma. Today, dermoscopy is recognized as a valuable method for evaluating pigmented skin lesions and following patients with a history of melanoma. 12,13 It is conceivable that, if both endo- genous and exogenous factors for a given individual with mela- noma remain the same, the clinical and dermoscopic features of subsequent lesions would be similar, especially if lesions are on the same body site, or occur around the same time. Should a trend towards similar-appearing subsequent MPMs exist, this may theoretically translate into earlier recognition of new melanomas. Ó 2013 The Authors British Journal of Dermatology (2013) 168, pp1267–1272 1267 BJD Ó 2013 British Association of Dermatologists