Exaggerated placental site

Exaggerated placental site, abbreviated EPS, is an uncommon benign pathology that is a gestational trophoblastic disease.

It was previously known as syncytial endometritis.

General

• Benign.

Definition:

• "Increased number" of implantation-site intermediate trophoblastic cells.

Note:

• Used to go by a terrible old term: syncytial endometritis:
  • Not syncytial -- mostly.
  • Not inflammatory.

Microscopic

Features:

• Intermediate trophoblast:
  • Abundant (eosinophilic) cytoplasm.
• Usu. adjacent to:
  • Chorionic villi.
  • Decidua - endometrial stromal cells with a nucleus central, eosinphilic cytoplasm, well-defined cell borders.
• No mitotic activity.
• Ectatic blood vessels.

DDx:

• PSTT.

Image

• EPS (webpathology.com).

IHC

• MIB1 ~0%.
  • Used to differentiate from PSTT.

See also

• Gestational trophoblastic disease.
• Endometritis.