Discordant Eosinophilic/T-Cell Chorionic Vasculitis in a Dichorionic Diamniotic Placenta.

Area of Science:

• Perinatology
• Immunopathology
• Placental Pathology

Background:

• Eosinophilic/T-cell chorionic vasculitis (ETCV) is an idiopathic placental lesion.
• Discordance in ETCV, affecting only one chorionic plate in twins, is a recognized phenomenon.
• Understanding the immunopathology of ETCV is crucial for diagnosing and managing adverse pregnancy outcomes.

Observation:

• A case of discordant ETCV in a diamniotic dichorionic placenta at 38 weeks gestation is presented.
• The affected female twin exhibited small for gestational age (25th percentile).
• Immunohistochemistry revealed specific T-cell and macrophage populations in the affected placental territory.

Findings:

• ETCV and high-grade villitis of unknown etiology (VUE) were identified, with VUE associated with chronic histiocytic intervillositis (CHI).
• Comparable TIA-1 expression was noted in both ETCV and VUE, suggesting a shared maternal inflammatory response.
• The combination of placental pathologies may have contributed to reduced fetal growth.

Implications:

• This case suggests a potential common antigen or chemokine pathway driving both maternal and fetal inflammatory responses in discordant placental conditions.
• Further research into these pathways could elucidate mechanisms of fetal growth restriction.
• Understanding discordant placental inflammation is vital for improving twin pregnancy outcomes.