Placenta
Nonneoplastic placental conditions and abnormalities
Noninfectious
Villitis of unknown etiology
Author: Mandolin S. Ziadie, M.D.
Last author update: 1 October 2011
Last staff update: 29 October 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Placental villitis of unknown etiology
Cite this page: Ziadie MS. Villitis of unknown etiology. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/placentavillitisunknown.html. Accessed May 30th, 2023.
Definition / general
- Chronic inflammatory cells within stroma of chorionic villi
- No causative organism
- Infiltrating cells have been shown to be maternal T cells, suggesting that this is an immune mediated disease
- Associated with fetal growth restriction, premature delivery and stillbirth (more common with recurrent disease)
- Seen in 3 - 5% of placentas with greater incidence (25%) in small for gestational age newborns
Grading
- Focal (low grade): small clusters of villi ( < 10) on a single slide
- Multifocal (low grade): small clusters of involved villi ( < 10) on multiple slides
- Patchy (high grade): larger clusters of villi ( > 10) on multiple slides
- Diffuse (high grade): large clusters of villi ( > 10) on all slides
Microscopic (histologic) description
- Lymphocytes and macrophages within the villous stroma, sometimes with granulomas and giant cells
- May be accompanied by chronic deciduitis with plasma cells, chronic chorioamniotis, perivillous fibrin, avascular villi and rarely with chronic intervillositis
