A Case of Ruptured Interstitial Ectopic Pregnancy: Ultrasonographic Appearance With Gross Pathology Correlate
Targeted right-lower-quadrant ultrasound was performed with a 9-MHz linear array transducer at the site of maximal tenderness with serial graded compression. The appendix was not visualized; however, the sonographer noted large-volume complex free fluid involving all abdominal quadrants (Fig. 1A, B). Per institutional protocol, the pelvis was examined transabdominally to document fetal heart motion. A fetus with heart motion was seen; however, it appeared eccentric to the left of the endometrial cavity on limited transabdominal images (Fig. 2). The radiologist was called, and decision was made to proceed with endovaginal imaging.
Endovaginal ultrasound confirmed a living fetus with a crown-rump length of 4.7 cm, corresponding to a gestational age of 11 weeks 3 days (Fig. 3). However, the gestational sac was completely eccentric to the endometrial cavity and located far to the left in the uterus (Fig. 4). This raised the possibility of an ectopic pregnancy in the interstitial portion of the left fallopian tube. This suspicion was confirmed by the absence of 360 degrees of myometrium surrounding the gestational sac, a requisite for an IUP (Fig. 5). Large-volume complex free fluid extending into the Morrison pouch was highly suggestive of rupture.
The gynecology service was immediately consulted, and urgent diagnostic laparoscopy confirmed a ruptured left interstitial ectopic pregnancy. The operation was therefore converted to open laparotomy, which demonstrated an approximately 6-cm left interstitial ectopic pregnancy (Fig. 6). Nearly 1 L of hemoperitoneum was noted, extending to the liver. A cornual wedge resection and proximal partial left salpingectomy were performed. The patient tolerated the surgery well, had no postoperative complications, and was discharged from the hospital 2 days later in good condition.