Necrotizing villitis and decidual vasculitis in the placentas of mothers with Behçet disease.

Behçet disease is an inflammatory disorder characterized by recurrent aphthous stomatitis, genital ulcers, uveitis, and skin lesions. There are occasional reports of neonatal Behçet disease suggesting a possible prenatal transmission. However, no placental Behçet disease lesion has been reported. Here, we report characteristic necrotizing inflammation in placentas and decidua from 2 patients with Behçet disease. The first patient had full-term delivery after uneventful medical therapy. The second patient underwent therapeutic abortion in the first trimester because of the fetal exposure to a potentially harmful medication for Behçet disease. Both placentas showed focal necrotizing villitis with neutrophil-dominant infiltration, similar to the characteristic Behçet disease lesions in other organs. Intervillous fibrinous exudates with neutrophilic infiltrates and granuloma-like histiocytic aggregates were present. The decidua also showed neutrophilic vasculitis. No evidence of infection was present. Our observation suggests that Behçet disease may involve placentas from the early stage of pregnancy. It may be implicated in potential fetal compromise and/or intrauterine transmission of the disease.