chronic villitis
Chronic villitis is characterized by chorionic villi infiltrated by lymphocytes, histiocytes, and sometimes plasma cells. In a small percentage of cases, an infectious agent can be demonstrated within areas of chronic villitis. However, the pathogenesis of most lesions is idiopathic.
Chronic villitis may represent the direct spread of chronic endometrial infection by bacterial organisms that are particularly problematic for culture.
References
Ernst LM, Crouch J, Rinder H, Howe JG. Bacterial etiology for chronic villitis is not supported by polymerase chain reaction for 16S rRNA DNA. Pediatr Dev Pathol. 2005 Nov-Dec;8(6):647-53. PMID: 16010482