Maternal malignant melanoma with placental metastasis: a case report with literature review.

Histologic detection of micrometastatic melanoma in the placenta led to the clinical diagnosis in the mother. Metastases were present in the intervillous space and in villous stroma. The infant has survived and has no evidence of disease at one year of age. The mother died of metastatic disease 6 months post-partum. Literature review shows that only 25% of infants with placental metastatic melanoma succumb to the disease. In a review series of 16 cases, there are some maternal clinical factors which seem to have some bearing on the likelihood of fetal metastasis and death from disease. Features that are associated with an unfavorable fetal/infant prognosis are: maternal age less than 30 years, primiparity, leg primary site, disease onset greater than 3 years prior to pregnancy, node-1 metastatic status prior to pregnancy, M4 status in third trimester, birth at greater than 36 weeks' gestation, male sex. Extent of penetration of metastases into the villi does not have prognostic significance.