Placenta
Nontrophoblastic neoplasms
Giant pigmented nevi of newborn

Author: Mandolin Ziadie, M.D. (see Authors page)

Revised: 19 October 2017, last major update November 2011

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PubMed Search: Giant pigmented nevi of newborn "loattrfull text"[sb]

Cite this page: Ziadie, M. Giant pigmented nevi of newborn. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/placentagiantnevi.html. Accessed October 21st, 2017.
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)