Placental gross / microscopic abnormalities, nonneoplastic
Geographic villi

Topic Completed: 1 October 2011

Minor changes: 18 February 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Geographic villi

Mandolin S. Ziadie, M.D.
Page views in 2019: 469
Page views in 2020 to date: 210
Cite this page: Ziadie MS. Geographic villi. website. Accessed June 4th, 2020.
Definition / general
  • Enlarged, dysmorphic villi with scalloped outlines without associated trophoblastic hyperplasia
  • Associated with chromosomal abnormalities, including trisomies 18, 13, 21; triploidy; XO
Gross images

Images hosted on PathOut server:

Trisomy 18 infant with overlapping digits

Microscopic (histologic) description
  • Enlarged, dysmorphic villi with scalloped outlines
  • Trophoblastic invaginations may be present
  • No / mild trophoblastic hyperplasia is seen
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