Histopathological characteristics of subsequent melanomas in patients with multiple primary melanomas

J Eur Acad Dermatol Venereol. 2014 Jan;28(1):58-64. doi: 10.1111/jdv.12055. Epub 2012 Dec 6.

Abstract

Background: Multiple primary melanomas (MPM) occur in up to 20% of melanoma patients, and subsequent tumours seem to have a favourable histopathological pattern.

Objective: A prospectively collected cohort of 194 patients with MPM was retrospectively reviewed to investigate clinical and histopathological features of first and subsequent melanomas.

Methods: Patients with MPM who were diagnosed at our Department (1985-2011) and who attended at least a follow-up control yearly were identified.

Results: The number of nevi was <10, 10-50 and >50 in 8.7%, 41% and 50.3% of patients respectively. Histopathological dysplastic nevi have been diagnosed in 105 patients. During a median follow-up of 58 months, 159 (81.9%), 24 (12.3%), 7 (3.6%) and 4 (2%) patients developed 2, 3, 4 and ≥ 5 melanomas, respectively. The median time to second primary melanoma was 45 months. The second primary melanoma was diagnosed within 1-year and after 5-year from the first melanoma in 36.6% and 17.3% of patients respectively. First and second primary melanomas were in situ in 41 (21%) and 104 (54%) patients respectively (P < 0.001). Among patients with ≥ 2 invasive melanomas (N = 80), median tumour thickness and ulceration of first and second primaries were 0.91 and 0.44 mm (P <0.001), and 32% and 7.7% (P = 0.001) respectively.

Conclusions: Subsequent melanomas occurred within 1-year from the appearance of the first melanoma in 36% of patients with MPM, while a late melanoma diagnosis was detected in 17% of cases. Second primary melanoma had favourable histopathological features. Our findings support long-term skin surveillance to detect subsequent melanomas at an early stage.

MeSH terms

  • Follow-Up Studies
  • Humans
  • Melanoma / pathology*
  • Prospective Studies
  • Skin Neoplasms / pathology