Chorangiosis: report of three cases and review of the literature.

The vascular lesions in the placenta form a heterogeneous group of possibly interrelated alterations. Gestational age distribution is different for chorangioma, chorangiosis, and chorangiomatosis; the pathogenesis is unclear, and histological features, especially those of chorangiosis and chorangiomatosis, frequently overlap. Chorangiomatosis shows intermediate features between chorangiosis and chorangioma. In this lesion, particularly when multifocal, the presence of small capillaries is similar to chorangiosis, but the gestational age is different from both chorangiosis and chorangioma. We present three cases of chorangiosis examined during one-year routine pathological analysis of placental tissue and report the histological, histochemical, and immunohistochemical features. Furthermore, we go into the difficulty of discerning the villous capillary lesions and the utility of this division, and describe the clinical effects of these lesions on fetal outcome.