Multiple primary melanomas: do they look the same?

Authors


  • 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.

Iris Zalaudek.
E-mail: iris.zalaudek@gmail.com

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 individual 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 dermoscopically 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 = 0·377). Similar thickness was associated with the occurrence of dermoscopically similar melanomas (19/30 cases, 63%; P = 0·039). Most (65%) of the synchronous lesions were similar, compared with 36% of nonsynchronous lesions (P = 0·029), and most (69%) of the melanomas on sun-damaged skin were similar, vs. 37% of melanomas on nonsun-damaged skin (P = 0·015; odds ratio 3·88, 95% confidence interval 1·11–13·98). The percentage 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.

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