Discussion
In this case report, we presented the challenging diagnosis and
management of a cornual ectopic pregnancy case. Cornual pregnancy is
rare, accounting for approximately 2-4% of all ectopic pregnancies
[1]. By definition, it refers to the implantation and development of
a gestational sac at the proximal and lateral regions of the uterus (aka
uterine horns or cornua). As with the majority of other types of ectopic
pregnancy, cornual pregnancy diagnosis is based on β-hCG measurments and
transvaginal ultrasound findings [2]. Ectopic pregnancy mortality
rate has been documented to be as high as 9-14%, rendering it the
leading cause of maternal death in the first trimester of gestation
[3], while cornual pregnancy In particular may lead to uterine
rupture in up to 48.6% of women within the 6th to 26th week of
gestation [6]. Given the aforementioned risk, accurate, timely
diagnosis and effective treatment are paramount for the safety of the
pregnant woman and in ensuring that she will be able to conceive and
gestate again in the future.
In the present case report, while clinical evidence was indicative of
ectopic pregnancy, the precise locus could not be located
ultrasongraphically. Therefore, MRI scanning was employed as an
alternative, which did manage to verify the diagnosis. Kao et al [7]
in their review describe that cornual pregnancy may be diagnosed via MRI
when the gestational sac is identified at the uterine cornu and is
surrounded by of an uninterrupted junctional zone that separates it from
the endometrium. They additionally stress the need for radiologist to be
adequately prepared to diagnose ectopic pregnancy, as ultrasonographic
assessment may not always suffice [7], similar to our experience
during the management of the present case.
Given the increased risk of adverse maternal outcomes, immediate and
effective management of cornual pregnancy is paramount. Conservative,
pharmacological management with methotrexate administration has been
tested as a non-invasive option for the treatment of cornual pregnancy,
via local or systemic methotrexate [8]. The first reported case of
successful resolution of ectopic pregnancy using this methodology was by
Tanaka et al [9]. Since then, multiple similarly successful cases
have been published [10]. Larger case series have also indicated the
efficacy of this approach, with Jermy et al [11] applying this
methotrexate regimen option during the management of 20 cases of ectopic
interstitial/cornual pregnancies. They reported successful pregnancy
resolution in 94% of cases, they do stress however that this method
should be reserved for cases with lower levels of β-hCG [11]. Cassik
et al [12] in their study of 42 women with ectopic
interstitial/cornual pregnancy concluded that low levels of initial
β-hCG were the only statistically significant predictor of a final
positive outcome, with mean β-hCG levels in the successful group being
3216 mIU/ml. These conclusions are also corroborated by the latest
version of the Royal College of Obstetrician and Gynaecologists
guidelines on the matter [8]. In our case, β-hCG levels were
increasing beyond the levels where conservative management and
monitoring would be a safe option; therefore, a more invasive approach
was preferred.
The traditional, well-established, safe approach to cornual ectopic
pregnancy is cornual resection via laparotomy or laparoscopy, while
hysterectomy may be reserved as a last resort option in life-threatening
cases [13,14]. Two primary methodologies have been proposed, namely
cornuotomy and corneal resection with salpingectomy, both being reported
as comparable, with regard to surgical complications and future
fertility outcomes [15]. Regardless of the applied technique,
adverse effects on future fertility potential, as well as increased risk
of uterine rupture in future pregnancies still remain prevalent risks
associated with these methodologies [4,16]. In a study by Lee et al
[17], the investigator compared the two approaches and concluded
that there were no statistically significant differences between the two
approaches apart from operative time (77.11 ± 23.97 min for cornual
resection versus 59.36 ± 19.32 min for cornuotomy, p=0.03). No other
surgical parameters demonstrated statistically significant differences
between the two methods, including no differences in the rate of
persistent interstitial pregnancy following treatment [17]. In our
case, since detailed imaging data regarding the sac’s location were
available and considering the patient’s wish to maintain her fertility
potential for future attempts, a less radical option was preferred
instead.
Hysteroscopic resection of cornual pregnancy is a minimally invasive
alternative approach that allows for direct visualization and removal of
all the products of gestation, without affecting the rest of the uterus.
The first such hysteroscopic resection was reported by Meyer et al
[18], performed under laparoscopic guidance. Sanz et al [19]
further expanded on the concept via hysteroscopy under ultrasonographic
guidance and Pal et al [5] combined laparoscopic and
ultrasonographic guidance to optimize their hysteroscopy. More recent
reports of successful hysteroscopic resection of pregnancy, following
failed initial methotrexate treatment, are indicative of the potential
of this technique as an alternative with reduced impact on future
fertility and maternal outcomes [20,21]. In our case hysteroscopy
was performed without prior methotrexate administration, since MRI data
were available and indicated that the products of gestations could be
safely removed without the need for laparoscopic intervention.
To our knowledge, this is the first reported case where a combination of
transvaginal ultrasound and MRI findings guided the successful
hysteroscopic removal of a cornual pregnancy, with the use of a simple
resectoscope, without any complications. Given the constant increase in
infertility rates, a method that allows for subsequent attempts at
conception and pregnancy, without affecting the fertility potential or
increasing the risk for uterine rupture during future attempts; such as
hysteroscopic resection, seems a promising option. Future research
should examine this alternative with larger multi-center studies and
patient series.