Placenta, villitis of unknown etiology

The findings are of a term placenta with excessive chronic inflammatory cells in numerous chorionic villi, diagnostic of chronic villitis. The common causes of villitis include bacteria, toxoplasma, herpes simplex, cytomegalovirus, and syphilis (T. pallidum) - TORCH organisms. In this case, further evaluation for these organisms was negative. The diagnosis for villitis of unknown etiology is a diagnosis of exclusion, but is commonly thought to have an immunologic cause.