Cesarean scar pregnancy: MRI feature

Abstract

A 34-year-old woman, gravida 4, para 2, presented at the emergency room with severe abdominal pain and red vaginal bleeding. Medical history revealed 2 previous cesarean sections at term gestation. Laboratory findings showed an elevated b-HCG consistent with an estimated gestational age of 6-7 weeks. Transabdominal ultrasound showed a well-circumscribed, thick-walled cystic mass within the lower part of the anterior myometrium. In the central cystic cavity a small mural nodule with discrete pulsatile flow was noticed. Subsequently a pelvic MRI exam was performed confirming the presence of the thick-walled, well-circumscribed mass in the lower part of the uterine wall (Fig. A). The mass extended beyond the expected contour of the uterus and no overlying myometrial tissue could be identified at the anterior border. At the cranial and posterior border of the mass a non-enhancing, T2 hypointense fibrous band was noticed, consistent with scar tissue of the two previous cesarean sections (Fig. B). The wall of the mass was T2 hyperintense, T1 iso-intense and showed a strong and heterogeneous enhancement following intravenous administration of gadolinium (Fig. C). The central portion of the mass was T2 hyperintense, T1 hypo-intense and showed no contrast enhancement. The cavity of the uterus was filled with T1 hyperintense, hemorrhagic fluid. A corpus gravidarum was seen on the left side. These findings were consistent of an ectopic pregnancy in a cesarean scar. Patient was successfully treated with a combination of chemotherapy and bilateral uterine artery embolization followed by a planned hysterectomy several weeks later