title: Eosinophilic/T-cell chorionic vasculitis.
abstract: Chorionic vasculitis is the hallmark of a fetal response in chorioamnionitis. There are five highly characteristic findings: (1) leukocyte migration is not concentric but rather radiates toward the infected amniotic fluid; (2) the infiltrate is primarily neutrophils; (3) multiple chorionic vessels, first veins and then arteries, are usually involved; (4) the infiltrate never extends into the vasculature of stem villi; and (5) it is rare in the absence of chorioamnionitis (or its precursors). Here we describe a new form of chorionic vasculitis characterized by an infiltrate composed primarily of eosinophils and CD3+ T lymphocytes that very focally involves a single chorionic vessel (artery or vein), that radiates away from the amniotic fluid (i.e., toward the intervillous spaces), and that may extend into the stem villous vasculature; this lesion occurs in the absence of any evidence of chorioamnionitis. During the past 7+ years, using accepted placental review criteria, we have examined 7104 placentas and identified 14 cases of eosinophilic/T-cell chorionic vasculitis (or related lesions). Although the frequency of diagnosis in the placentas examined was 0.197%, its true incidence cannot be estimated because of its very focal nature and the limited nature of placental disk sampling. Its etiology and significance are unknown, but it may represent a focal immune-mediated vasculitis.
authors.affiliation: Department of Pathology and Laboratory Medicine, IWK Health Centre and Dalhousie University, 5850 University Avenue, Halifax, Nova Scotia B3H 1V7, Canada. robert.fraser@iwk.nshealth.ca
authors.forename: Robert B
authors.initials: RB
authors.lastname: Fraser
authors.forename: James R
authors.initials: JR
authors.lastname: Wright
mesh_terms: D015703:Antigens, CD; D002823:Chorion / Q000378:metabolism / Q000473:pathology*; D004802:Eosinophilia / Q000378:metabolism / Q000473:pathology; D004804:Eosinophils / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D010922:Placenta Diseases / Q000378:metabolism / Q000473:pathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000378:metabolism / Q000473:pathology; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D014657:Vasculitis / Q000378:metabolism / Q000473:pathology*
chemical_list: D015703:Antigens, CD