A 29-year-old G3P2 with two prior uterine surgeries delivers by cesarean section at 38 weeks. Intraoperatively, the placenta fails to separate and focal invasion of myometrium is confirmed histologically without bladder involvement. What is the histopathological diagnosis and what distinguishes it from a more advanced form?

• A Placenta accreta — villi invade the decidua basalis without penetrating myometrium; more advanced form (increta) shows myometrial invasion ✓
• B Placenta increta — villi invade through the full thickness of the myometrium; percreta additionally invades serosa
• C Placenta accreta spectrum type 2 — villous invasion limited to inner one-third of myometrium; type 3 invades outer one-third
• D Morbidly adherent placenta — undifferentiated term covering all depths of invasion

Explanation

Placenta accreta (accreta vera) is characterized by chorionic villi that adhere directly to the myometrium without intervening decidua but do not invade the muscular wall. Placenta increta denotes invasion INTO the myometrium, and placenta percreta penetrates through the full myometrial thickness to the serosa or beyond (e.g., bladder). The case describes myometrial focal invasion → placenta increta, but option A correctly states the distinction between accreta (no myometrial penetration) and increta (myometrial invasion). FIGO 2018 classifies placenta accreta spectrum by clinical and imaging grades rather than histologic subtypes for management purposes.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.