Cite this page: Ziadie MS. Giant pigmented nevi of newborn. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/placentagiantnevi.html. Accessed July 18th, 2019.
Definition / general
- Pigmented melanocytes within the placental villi, associated with giant congenital melanocytic nevus of the fetus (see skin - melanocytic tumor)
Microscopic (histologic) description
- Benign pigmented nevus cells within the villi
- Although some giant melanocytic nevi can undergo malignant transformation, the benign appearance and lack of vascular involvement favors a congenital rather than a metastatic process
- Differential diagnosis includes metastatic melanoma of maternal or fetal origin (atypical cells with vascular involvement)