WEDNESDAY, Nov. 12, 2025 (HealthDay News) -- Pregnancy-associated melanoma (PAM) demonstrates some distinct clinical features, and more than half develop on a preexisting nevus, according to a study published online Oct. 24 in the Journal of the European Academy of Dermatology & Venereology.

Maria Kostaki, M.D., Ph.D., from the General Hospital of Athens G. Gennimatas in Greece, and colleagues characterized the epidemiologic and clinicopathologic features of PAM and whether these tumors differ from melanomas not associated with pregnancy. A total of 1,270 women of reproductive age (15 to 49 years) diagnosed with melanoma between 2012 and 2022 were identified across six melanoma centers in five European countries; 70 cases (5.5 percent) were classified as PAM.

The researchers found that women with PAM were younger and more likely to have a high nevus count than non-PAM women. Most PAMs (80.0 percent) were superficial spreading; the mean Breslow thickness was 1.16 mm, and 12.9 percent were ulcerated. More than half (57.1 percent) developed on a preexisting nevus. The groups had similar histopathologic features, apart from tumor-infiltrating lymphocytes (TILs), with significantly more dense TILs in non-PAM tumors. There was no between-group difference noted in recurrence-free survival; the five-year recurrence-free survival rate was 95 percent.

"The frequent occurrence of PAM on preexisting nevi underscores the importance of increasing public awareness regarding the need for dermatologic evaluation of any suspicious cutaneous lesions during pregnancy," the authors write.

Several authors disclosed ties to the biopharmaceutical industry.

Abstract/Full Text