Focal Chorangiosis: Does It Have Clinical and Pathologic Significance?

Chorangiosis is a proliferation of capillaries in terminal chorionic villi and is considered to be a marker for hypoxia and poor clinical outcome. Not all cases with hypervascular villi meet the generally accepted diagnostic criteria as reported by Altshuler. Our aim was to evaluate cases with villous hypervascularity that do not meet the diagnosis of chorangiosis, in which increased vascularity was present in a significant portion of the villous tissue but was not a diffuse process, which we call focal chorangiosis, to ascertain whether there were clinical or pathologic associations.

A total of 175 placentas with the finding of focal chorangiosis and 176 maternal age- and gestational age-matched controls were evaluated retrospectively. We defined focal chorangiosis as villous hypervascularity that did not meet criteria for a diagnosis of chorangiosis, but in which there was involvement of at least 50% of villi on at least 2 of 3 slides of placental tissue or involvement of all the villi on 1 slide. In these focal areas, the criteria of 10 capillaries in each of 10 villi in ten 10× microscopic fields were required.

We found that focal chorangiosis is associated with a decrease in Apgar scores, increased placental weight, fetal vascular thrombosis (fetal vascular malperfusion), umbilical cord abnormalities, increased fetal nucleated red blood cells, villous dysmaturity, and increased rate of vaginal delivery.

Many of these associations are shared with chorangiosis as traditionally defined, suggesting that focal chorangiosis is a significant finding that should be reported.