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Updated: Apr 23, 2026

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Merkel cell carcinoma: differences between sun-exposed and non-sun-exposed variants--a clinical analysis of 36 cases
Joaquim Marcoval1, Josep Ramon Ferreres, Rosa María Penín
1Department of Dermatology, Bellvitge Hospital, Bellvitge Biomedical Research Institute, Barcelona, Spain.
Background:
There are few studies focusing on the clinical characteristics of Merkel cell carcinoma (MCC).
Objective:
To retrospectively analyze the clinical features of our patients and their relationship with sun exposure.
Methods:
Thirty-six patients diagnosed with MCC (20 men and 16 women, mean age 72.08 years) were included in the study.
Results:
21 patients developed MCC in sun-exposed skin and 15 patients in non-sun-exposed areas. MCC was >2 cm in 19 cases. Six of the 7 patients who died as a result of MCC had non-sun-exposed tumors. Only tumor size >2 cm significantly influenced survival (p = 0.033).
Conclusion:
Sun-exposed lesions tended to be <2 cm in diameter and were more common in men, while non-sun-exposed tumors were larger, usually occurring in women and carrying a greater likelihood of death by MCC. Non-sun-exposed tumors usually present as fast-growing, multilobar nodular lesions with a smooth shiny surface.
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