Mayer-Rokitansky-Kuster-Hauser syndrome type I

A 16-year-old female was referred to our department for MRI of the pelvis due to primary amenorrhea.

MRI revealed absence of a normal uterus, cervix and vagina. A small triangular midline soft tissue structure, lying above the bladder dome was seen (Figure 1). Both ovaries were intrapelvic, with normal appearance (Figure 2). A unilocular right ovarian functional cyst (Figure 2b), with hemorrhagic components in the dependent part, was detected.

Bilateral rudimentary uterine buds were revealed (Figure 3). The right uterine bud was located at the same plane with the paired ovary, had a mean volume of 2.7ml and partly a three-layer differentiation (Figure 3). The left uterine bud was located posteriorly and caudal to the ipsilateral ovary had a mean volume of 1.44ml and absence of layer differentiation. No intraluminal blood was detected (Figures 2b, 3). Bilateral thick fibrous bands extending from uterine remnants onto the triangular midline structure were seen (Figure 4).

A moderate amount of fluid in the Douglas space was found to coexist. No renal abnormalities were detected (Figure 5).

MRKH syndrome is a rare congenital malformation that results from the disruption of embryonic development of Mullerian ducts. It is characterized by complete/partial agenesis of uterus and upper two-thirds of vagina, with normal bilateral ovaries, normal secondary sex characteristics and a normal female karyotype (46,XX).

MRKH syndrome is typically diagnosed during adolescence, and it has a prevalence of 1 in 4000-5000 live female births.  The commonest clinical presentation is primary amenorrhea. The aetiology is not yet known, although genetic and environmental factors have been implicated.

MRKH syndrome is classified as Type I [typical], characterized by isolated ureterovaginal aplasia and Type II [atypical], associated with extragenital malformations, including renal, skeletal, cardiac or middle ear anomalies [1-7].

Treatment allows patients to have sexual function, with possible acquisition of reproduction through assisted reproduction techniques or surrogacy. A detailed evaluation of uterus, ovaries, and vagina is therefore important. A small cavitated uterine remnant may be surgically reconstructed to create a functional uterus. Cavitated buds can potentially cause cyclical pain or endometriosis and may need surgical removal. The exact location of the ovaries is important for in-vitro fertilization or surrogacy [1-7].

Ultrasonography is often the initial imaging modality for the diagnosis of MRKH syndrome. However, small uterine remnants, ectopic ovaries or intrauterine endometrium may not be thoroughly assessed by US. Moreover, a partially developed small rudimentary uterine remnant may be misinterpreted as a small tubular prepubertal uterus.

MRI represents an excellent technique for the detailed preoperative evaluation of patients with suspected MRKH syndrome. Rudimentary uteri, especially bilateral, is a common MRI finding, as in our case. Uterine remnants have a caudal relationship with the paired ovary, even when it is ectopic. They can be relatively large, especially the unilateral rudimentary uterus. They have variable degrees of differentiation, with one to three layers seen. Functional endometrial tissue, resulting in intraluminal blood or adenomyosis, may be seen,  more often in unilateral remnants, presenting with pelvic pain. Other typical MRI findings include a midline triangular soft tissue structure lying above the bladder dome and bilateral fibrous bands extending from rudimentary uterine buds onto this triangular structure. Ovaries in MRKH syndrome are ectopic in up to 40% of patients. The lower third of the vagina can be complete, may be terminated with a blind pouch or may be atresic [1-7].