Decidiosis of the cesarean scar

Specialty: Gynecology and breast.

• Ectopic decidual reaction in the abdominal wall
• decidualized endometriosis of the cesarean section scar

Why it occurs

• Massive hormonal stimulation by progesterone during a subsequent pregnancy on previous foci of endometriosis latently located in the scar of a previous cesarean section, inducing massive decidualization of the endometriotic stroma that rapidly increases in size and can become inflamed or bleed

Initial workup

High-resolution soft tissue ultrasound of the abdominal wall (shows a hypoechoic, lobulated, richly vascularized solid mass using color Doppler, located under the subcutaneous cellular tissue in relation to the fascia). Magnetic Resonance of the abdomen and pelvis without contrast (due to pregnancy) to precisely define the anatomical location with respect to the rectus abdominis muscles and rule out infiltration of the pregnant uterus. Core needle biopsy (CNB) if there are reasonable diagnostic doubts with a wall sarcoma.

Standard management

• There are no drugs indicated for this symptom during pregnancy. Pain is managed with Paracetamol 500-1000 mg orally every 8 hours. Conservative management is advised during pregnancy, as the mass usually decreases drastically in size or disappears spontaneously after childbirth due to the physiological drop in progesterone levels. If pain persists or continues after 3-6 months postpartum, complete surgical resection of the painful scar with free margins under local or general anesthesia is indicated (note: avoid unnecessary surgical manipulation during pregnancy).