IS Case 263: Left unicornuate uterus with noncommunicating right rudimentary horn

Keith Forrest Dockery, MD

Imaging Sciences URMC 2009
Publication Date: 2009-06-26


Patient is a 34-year-old female with history of several miscarriages, preterm delivery, and ruptured ovarian cysts.

Her initial work-up, including obstetric exam, laboratory data, and transvaginal ultrasound were initially described as normal. Years later, after multiple miscarriages, she underwent a hysterosalpingogram (HSG) and MRI of the pelvis to evaluate for uterine abnormalities. The HSG indicated unicornuate uterus, i.e. non-visualization of the right uterine horn. MR established left unicornuate uterus with a rudimentary right uterine horn, which did not communicate with the left. For the current study, patient had returned with abdominal pain and underwent CT of the abdomen and pelvis.


The hysterosalpingogram revealed only a left-sided unicornuate uterus with ipsilateral free spillage of contrast. The contralateral uterine horn is nonvisualized with absence of right sided contrast spillage.

Magnetic resonance imaging sequences included: axial T1-weighted; axial T2-weighted with fast recovery, fast spin echo; and coronal reformat T2-weighted with fat saturation. MR images revealed T2 central hyperintensity in the uterus and and right rudimentary horn.

Computed tomographic images revealed normal enhancement in the left-sided unicornuate uterus and right rudimentary horn.


Left unicornuate uterus with noncommunicating right rudimentary horn


Unicornuate uterus is a müllerian anomaly commonly associated with rudimentary horn. Diagnosis of unicornuate uterus and rudimentary horn is important since rudimentary horn pregnancies usually (70-90%) rupture in the second or third trimester (before 20 weeks) causing life-threatening hemorrhage. Incidence of rudimentary horn pregnancy is 1 in 76,000-140,000 pregnancies. 90% of rudimentary uterine horns are noncommunicating.

Delay in diagnosis places the patient at risk from spontaneous abortion. In this case, the patient was undiagnosed for more than a decade, despite obstetric exam, Cesarean delivery, exploratory laparotomy, transvaginal ultrasound and computed tomography. The bimanual exam can be helpful for ectopic pregnancy: Baart de la faille’s sign is a palpable mass extending outward from uterine angle, and Ruge Simon syndrome is displacement of fundus to contralateral side with rotation of uterus and elevation of the affected horn. Hysterosalpingogram and MR are helpful uterine imaging modalities, with CT providing general abdominal and pelvic evaluation. Ultrasound is operator-dependent, but remains a standard tool for the evaluation of pelvic pain, especially concerning uterine and adnexal etiologies. Comparison of modalities for uterine abnormalities has revealed accuracies, follows: MR 100%; US 90%; HSG 30%.


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