Key findings:

• left unicornuate uterus without rudimentary horn
• patent left fallopian tube
• morphologically normal ovaries with distant positioning of the right ovary anterior to the iliopsoas
• malrotated and dysplastic right pelvic kidney

This patient has a unicornuate uterus, which resulted from normal development of the left mullerian duct and arrested development of the right mullerian duct. 40% are associated with renal anomalies ipsilateral to the rudimentary horn.

As in this case, absent rudimentary horn subtype presents minimal risk and does not require surgical intervention. Endometrial tissue within a non-communicating rudimentary horn is an important clinical finding that puts the patient at risk for endometriosis, and can be determined with MRI or ultrasound.

HSG can identify a unicornuate uterus, but is not sufficient to exclude the presence of an noncommunicating rudimentary horn. Thus, MRI was performed to complete the anatomic evaluation.