Placenta
Nontrophoblastic neoplasms
Chorangiosis

Author: Shipra Garg, MD. (see Authors page)

Revised: 25 October 2017, last major update October 2017

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Chorangiosis placenta
Cite this page: Garg, S. Chorangiosis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/placentachorangiosis.html. Accessed November 22nd, 2017.
Definition / general
  • Altshuler criteria: More than 10 capillaries in at least 10 terminal villi in 10 or more noninfarcted areas in at least 3 low power fields of the placenta (Arch Pathol Lab Med 1984;108:71); normal villi rarely have > 5 capillaries/villous
  • Capillary hyperplasia is due to chronic placental hypoperfusion or low grade tissue hypoxemia (Gynecol Obstet Invest 2012;73:141)
  • May be seen in pre-eclampsia, diabetes mellitus, placentomegaly, high altitudes, drugs and urinary tract infections
  • Associated with neonatal morbidity / mortality
Essential features
  • Chorangiosis is vascular hyperplasia in the terminal chorionic villi, resulting from longstanding low grade hypoxia in the placental tissue (Congenit Anom (Kyoto) 2009;49:71)
  • Alteration of the terminal villus, characterized by an abnormal growth of fibrous and vascular tissues, with an increased number of capillaries in placental areas
Pathophysiology
  • Chronic hypoperfusion and tissue hypoxemia may lead to an excessive villous neoangiogenesis and to a high proliferative activity of connective tissue, probably mediated by growth factors (VEGF, bFGF and PDGF)
Etiology
  • Higher incidence in maternal pathological conditions such as preeclampsia, diabetes mellitus, drug ingestion and urinary tract infections
  • Incidence is higher in women living at high altitudes, in maternal anemia and in women who smoke (J Pregnancy 2014;2014:193925)
  • Also associated with placental alterations such as single umbilical artery, placental abruption, amnion nodosum, villitis and umbilical cord anomalies
  • Complications include major fetal congenital anomalies or low Apgar index
Case reports
Gross description
  • Associated with single umbilical artery and other umbilical cord anomalies, retroplacental hematoma (abruptio placentae) and placenta previa
Microscopic (histologic) description
  • More than 10 capillaries in more than 10 terminal villi in at least 10 different noninfarcted areas in 3 low power fields of the placenta
  • Capillaries have distinct basement membranes but are not surrounded by a continuous layer of pericytes or associated with stromal fibrosis
  • May be associated with other features of villous dysmaturity, chorangioma, amnion nodosum, chronic villitis and fetal thrombotic vasculopathy (FTV)
  • Must distinguish from congestion (vessels appear prominent but are normal in number) and tissue ischemia (has shrunken coagulated villi)
Microscopic (histologic) images

Images hosted on other servers:

Chorangiosis very high magnification

Chorangiosis



Images contributed by Dr. Semir Vranic

H&E 20x

Positive stains
  • Capillary endothelial cells are highlighted by CD31, CD34
Differential diagnosis
  • Chorangioma: nodular lesion composed entirely of capillary vascular channels with surrounding trophoblasts; analogous to hemangiomas occurring elsewhere
  • Chorangiomatosis: heterogeneous and less well defined lesion with intermediate features between chorangioma and chorangiosis
    • Hyperplastic capillaries surround larger vessels in central cores of stem villi
    • Increased number of perivascular bundles of reticulin fibers and pericytes
  • Congestion: prominent capillaries in the villi but there is no numerical increase in the number of capillaries
Board review question #1
Which of the following is true?

  1. Chorangiosis is also known as hemangioma of the placenta.
  2. Chorangiosis is always seen in women with diabetes mellitus, while chorangiomatosis is always seen in women with pre-eclampsia.
  3. In chorangiosis, each capillary shows a distinct basement membrane but there is no increase in perivascular pericytes or reticulin bundles.
  4. All of the above.
Board review answer #1
C. In chorangiosis each capillary shows a distinct basement membrane but there is no increase in perivascular pericytes or reticulin bundles. Answer A is false because chorangioma, not chorangiosis, is known as hemangioma of the placenta. B is false because diabetes mellitus is associated with, but not always seen with chorangiosis.