Ectopic pregnancy is commonly located in the fallopian tube. Nevertheless, two unusual types of ectopic pregnancy, intramural pregnancy and rudimentary horn pregnancy, seriously threaten maternal life. The diagnosis and treatment of these unusual implantation sites present a clinical challenge. In this study, we illustrated the two unusual types of ectopic pregnancy and summarized the current data regarding diagnosis and optimal treatment from our experience.
A 21-year-old female, G3P1A1, presented to our hospital because ultrasound scan revealed intrauterine tissue residues after two curettage operations. In another hospital, two months ago, she was initially misdiagnosed with a missed abortion at approximately 8 weeks of gestation and then suction curettage was performed. However, she suffered persistent vaginal bleeding after the first curettage and ultrasound showed intrauterine tissue residues. Therefore, the second curettage was carried out. However, the biopsy specimen was not obtained in the two curettage operations. In our hospital, transvaginal sonography revealed an ill-defined fundal mass (30 mm × 25 mm) near the left fundus. Color-flow Doppler analysis revealed high blood flow at the periphery of the fundal mass, and it was difficult to differentiate the boundary from the myometrium or endometrial cavity (Figure
(a) Color Doppler transvaginal sonography of the transverse view of the uterus showing an endometrial cavity (EC) and mass (M). (b) Hysteroscopy reveals an empty uterine cavity without gestational tissue. Laparoscopic findings showing an intramural pregnancy near the left fundus. Histological specimens showed that chorionic villi (CV) were identified in the intramural pregnancy.
We suspected an embryonic left cornual pregnancy or an invasive molar pregnancy and therefore decided to perform hysteroscopy and laparoscopy. The initial hysteroscopy revealed an empty uterine cavity with endometrial thinness and visible bilateral ostia, which negated the possibility of cornual pregnancy (Figure
A 26-year-old female, G1P0, presented to the emergency department at her 53rd day of amenorrhea with abdominal pain. She had normal menstrual periods without the history of dysmenorrhoea. At admission, the patient’s general condition was good and her vital signs were normal. Pelvic examination revealed a single cervix with normal uterus on the right side. On the left side, a soft painful mass (60 × 60 mm) was palpable. An ultrasound investigation was performed, including an initial two-dimensional (2D) ultrasound assessment of her pelvis with the selection of the region of interest and the acquisition of a three-dimensional (3D) ultrasound. The investigation revealed a right unicornuate uterus with the size of 66 mm × 42 mm × 40 mm and an endometrial thickness of 8 mm. Lining her left ovary, a noncommunicating rudimentary horn with a gestational sac of 33 × 20 mm was described. There was an 11 mm long embryo in the gestational sac with visible fetal heart beat. Both ovaries were normal in terms of morphology and volume (Figure
(a) Ultrasound revealed a right unicornuate uterus (UT) with an endometrial cavity (EC) and a noncommunicating rudimentary horn (RH) with a gestational sac (GS). There is an embryo (E) in the gestational sac with visible fetal heart beat. (b) Laparoscopy findings showing a left noncommunicating rudimentary uterine horn attached to a normal right horn.
The patient opted for laparoscopic surgery. Laparoscopy confirmed a left noncommunicating rudimentary uterine horn attached to a normal right horn. The wall of rudimentary horn was thin. Bilateral tubes and ovaries were normal. The rudimentary horn was excised with the ipsilateral fallopian tube (Figure
A 27-year-old G1P0 woman at 15+6 weeks of amenorrhea presented with severe abdominal pain 2 days before admission. At arrival, she was noted to be in hypovolemic shock with pallor, hypotension (88/47 mmHg), and tachycardia. The abdomen was tense with the symphysis-fundal height of 18 weeks. No vaginal bleeding was noted. She had abdominal pain 7 days ago, but she was told that the pregnancy was normal in another hospital. No other significant histories were noted. Further assessment with transabdominal ultrasound showed a viable fetus with the 16-week size beside the normal uterus. Much abdominal effusion was described. Pregnancy in a rudimentary horn of the uterus was suspected with a differential diagnosis of an abdominal pregnancy. Then 3 mL of nonclotting blood was pumped by abdominal paracentesis.
An emergency laparotomy was performed immediately. Intraoperative findings revealed a unicornuate uterus with left rudimentary horn pregnancy (Figure
Intraoperative findings revealed a unicornuate uterus with left rudimentary horn pregnancy.
Intramural pregnancy is one of the rare types of ectopic pregnancy. It refers to a uterine conceptus within the myometrium, without the connection with the fallopian tubes or endometrial cavity. This type of pregnancy accounts for less than 1% of all ectopic pregnancy [
It is difficult to preoperatively diagnose the intramural pregnancy, which is often misdiagnosed. Diagnostic modalities may include ultrasound, a computed tomography (CT) scan, and magnetic resonance imaging. The diagnosis of intramural pregnancy requires clear visualization of the endometrial-myometrial junction in order to delineate the endometrial cavity and detect extension of trophoblast into the myometrium. According to the ultrasound characteristics, Luo et al. divided the intramural pregnancy into three types: gestational cyst type, mass type, and uterine rupture type. The gestational cyst type or mass type presented with an empty uterus and a gestational sac or mixed mass in the myometrium, which can be separated from the endometrium. The sac or mass did not communicate with the uterine cavity. Abundant blood flow was observed around the sac or in the mass, while massive hemoperitoneum was found in the uterine rupture type [
The management of intramural pregnancy depends on the size of the lesion, patient status, and also the desire for future fertility. Previous treatment modalities for intramural pregnancy include expectant management, surgical enucleation, uterine artery embolization, systemic or local methotrexate administration, and hysterectomy [
Rudimentary horn pregnancy (RHP), described in cases
Rudimentary horn pregnancy represents a very serious life-threatening pathological condition. Though the maternal mortality rate has been reduced from 18% in the nineteenth century to 0.5% now, the importance of early diagnosis to prevent morbidity and mortality cannot be overemphasized [
The surgery of excising the rudimentary horn and ipsilateral fallopian tube is the main treatment method of rudimentary horn pregnancy. When the rudimentary horn pregnancy is small and facilities are available, it may be possible to resect it by laparoscopy. Others described the administration of methotrexate for termination of an early pregnancy in a rudimentary horn followed by elective laparoscopic resection [
Two unusual types of ectopic pregnancy (intramural pregnancy and rudimentary horn pregnancy) were illustrated and discussed in the paper. Ectopic pregnancy at the unusual location is encountered much less frequently but is more morbid. The treatment of these types of unusual ectopic pregnancy may not be as commonplace as the treatment of tubal pregnancy. However, through early diagnosis and effective planning, the treatments can be equally effective.
This paper had received exemption from the local IRB.
The authors declare that there is no conflict of interests regarding the publication of this paper.