Congenital vaginal atresia with concealed haematocolpos and associated unicornuate uterus

Clinical History

A thirteen-year-old girl presented to the hospital with intermittent lower abdominal pain. The patient had not achieved menarche yet. On clinical examination, a mass was palpable in the pelvic region. Clinically she was thought to have an imperforate hymen.

Imaging Findings

Pelvic ultrasound showed a grossly distended vagina filled with moving internal echoes, diagnostic of haematocolpos.
The endometrial cavity of the uterus also contained a fluid collection.

The gynaecologist noticed absence of an expected bulge in the hymen in the patient with haematocolpos. Hence MRI was requested to rule out the possibility of Mayer Rokitansky Kuster Hauser syndrome.

Pelvic MRI showed a grossly distended and elongated proximal vagina containing subacute blood, which was hyperintense on T1WI and hypointense on T2WI.
The lower vagina was not visualised in its expected location in sagittal as well as axial images, suggesting vaginal atresia.
The uterus was deviated to the left side, had an abnormal, elongated ‘banana’ configuration, suggestive of an ‘Unicornuate uterus’. No rudimentary horn was visualised. The endometrial cavity of the uterus as well as the cervical canal was filled with subacute blood, suggestive of haematometra. The haematometra communicated with the haematocolpos through a widely open cervical canal.

Discussion

Embryologically the uterus, fallopian tubes and upper two thirds of vagina develop from paired Mullerian ducts. At approximately 10 weeks following conception, the ducts migrate caudally, undergo fusion and subsequent recanalization.
Unicornuate uterus results from non-development or rudimentary development of one Mullerian duct. The other Mullerian duct is fully developed and the uterus has a ‘banana’-shaped configuration. A rudimentary horn may be present, which may or may not communicate with the endometrial cavity. [1] Normal uterine zonal anatomy is maintained in the unicornuate uterus; whereas the rudimentary horn shows a lower signal. No rudimentary horn was seen in our case.

The lower third of vagina develops from the urogenital sinus. So atresia of the lower vagina is usually not considered a Mullerian anomaly [2].
In our case, strangely atresia of the lower vagina was associated with a unicornuate uterus. No cloacal anomalies were seen. No renal or skeletal anomalies were seen.
Differential diagnosis in our case would have been an imperforate hymen presenting with haematocolpos. These patients also usually present at puberty with pelvic pain and mass. Symptoms arise at puberty due to retention of menstrual blood and urinary symptoms due to compression of urethra. Ultrasound can identify a distended vagina packed with internal echoes. Involvement of endometrial cavity or fallopian tubes can occur, with haematometra and haematosalpinx respectively. Clinical examination can reveal the imperforate hymen with a bulge. Imperforate hymen is the most frequent congenital abnormality of the female genital tract and its surgical treatment involves a simple hymenotomy.
Treatment for vaginal atresia depends on presence or absence of functioning endometrial tissue.
In a patient with functioning endometrium and an obstructed outflow tract (atretic vagina, as in our case), temporary hormonal manipulation of the menstrual cycle is necessary till a new outflow tract can be reconstructed.
When there is no functioning uterus/endometrium, like in cases of uterine agenesis or Mayer Rokitansky Kuster Hauser syndrome, the surgical goal is to create a blind-ending vaginal pouch.

Differential diagnosis in peripubertal girls presenting with pelvic pain and pelvic mass can be varied. Some of the common causes would include an ovarian cyst or ovarian neoplasm, urinary retention and pelvic kidney. It is important to be aware of haematocolpometra as an important differential diagnosis in this group of patients. A pelvic ultrasound and clinical examination will usually clarify the matter.

Differential Diagnosis List

Final Diagnosis

Congenital vaginal atresia with concealed haematocolpos and associated unicornuate uterus.

URL:	https://www.eurorad.org/case/12104
DOI:	10.1594/EURORAD/CASE.12104
ISSN:	1563-4086