Angular and Interstitial Ectopic Pregnancies: A Clarification of Terms and Literature Review

Angular pregnancy is an exceedingly rare diagnosis, with less than 100 reported cases. Angular pregnancy is important to distinguish from ectopic pregnancies due to the fact that they have the potential to be viable while true ectopic pregnancies do not. As such, angular pregnancy requires starkly different management. Inappropriate use of the terms angular, interstitial, and cornual indicates a general misunderstanding of what makes these diagnoses unique. Misunderstanding leads to misdiagnosis and consequent mismanagement. Our experience with cases of women with angular and interstitial ectopic pregnancies is instructive as it illustrates effective diagnosis and differing management of these two diagnoses. In the two angular pregnancy cases, transvaginal ultrasonography was employed to confirm the diagnosis, which showed a lack of the interstitial line sign, contiguity of the decidua and endometrium, and an endomyometrial mantle thickness between 5 and 8 mm. One patient's angular pregnancy ultimately ruptured and was successfully managed with fully robotic cornual resection and unilateral salpingectomy, while the other progressed to term normally without complication. The patient with an interstitial ectopic pregnancy was also managed surgically, although with laparoscopic cornuotomy and salpingectomy.