Placenta Increta Presenting as Exaggerated Placental Site Reaction

Exaggerated placental site (EPS) is usually an incidental finding seen in curettings after an abortion. Placenta increta is, by definition, a disease that damages and destroys myometrium; however, prior literature has not paid sufficient attention to the role of myometrium in its pathogenesis and diagnosis. We present an unusual case of placenta increta in a hysterectomy performed for uterine perforation after curettage for the termination of pregnancy at 18 weeks. The initial histologic section of the implantation site suggested EPS. Actin stains showed degenerated inflamed muscle at the EPS-like site, keratin stains showed interstitial trophoblast in the zone of myometrial damage, and the wall of the corpus was grossly thinned under the placenta. The myometrial damage may have softened the wall, predisposing to uterine perforation by the curettage procedure.