Imperforate hymen presenting as painless acute urinary retention and constipation

A 14-year-old girl presented to the Emergency Department with a 2-day history of painless acute urinary retention and constipation. Her last bowel movement was 2 days previous and was described as ‘rabbit dropping’ consistency. She described only managing to pass small volumes of urine. She denied any history of vomiting or persistent or cyclical abdominal pain and had not yet started menses. She denied sexual activity and had a negative urinary pregnancy test. Her secondary sexual development was Tanner stage 4 with development of breasts and genitalia which was appropriate for her age. Following bladder catheterization, 760 ml of urine was drained.

Abdominal examination revealed a non-tender mass arising from the pelvis. She underwent an abdominal ultrasound which demonstrated a large pelvic cystic lesion. A subsequent MRI pelvis was performed which demonstrated a large well-defined structure arising from the pelvis measuring 11 × 12 × 20 cm. The vagina appeared distended with layered blood, which represented haematocolpos (Figure 1).

Figure 1.

MRI pelvis ( Sagittal section T2 weighted) demonstrating a distended vagina (A) and uterus (B), in keeping with haematocolpos.

The patient underwent a vaginal examination, which demonstrated a bulging imperforate hymen with classical blue colouration, indicating a large collection of menstrual blood behind it (Figure 2). She was counselled and consented for surgical hymenectomy under general anaesthetic. At operation, she underwent a cruciate incision of the imperforate hymen. Seven hundred and fifty milliliters of accumulated menstrual blood was drained.

Figure 2.

A bulging imperforate hymen with classical blue colouration, indicating a large collection of menstrual blood behind it.

The patient made an unremarkable recovery and was discharged on the same operative day. She was reviewed 3 months later. Her follow-up pelvic ultrasound demonstrated a normally sized non-distended uterus. She reported she had commenced regular menstrual cycles.

DISCUSSION

Imperforate hymen is a rare finding affecting 0.05–0.1% of the female population (1,2,3). The hymen is a transverse embryological remnant of mesodermal tissue which will usually perforate during embryonic development. Failure of this canalisation process results in an imperforate hymen with subsequent obstruction of uterine secretions (1).

Patients may present as newborns in the neonatal period with hydrocolpos after maternal oestrogen stimulation cause utero-vaginal secretions. Less frequently, the diagnosis may be detected prenatally, manifesting as hydrocolpos or hydrometrocolpos, or hydronephrosis on fetal ultrasonography (4). More commonly, patients present in adolescence at the onset of menses. The accumulation of menstrual blood within the uterus and cervix commonly present as abdominal pain, amenorrhea, constipation, pelvic mass bowel obstruction and urinary retention. Hydronephrosis and renal failure have also been reported (1,2,3,5,6).

Physical examination is essential to differentiate between an imperforate hymen and other abnormalities such as vaginal atresia, cervical atresia or vaginal septum (the management of which is different). The presence of a characteristic bulging blue-colored hymen (indicating a collection of blood) is usually diagnostic (6). The diagnosis of imperforate hymen may be delayed because gynaecological examination is not always routinely performed or considered in patients of this age group (2).

Radiological diagnosis can be achieved with ultrasound, which usually demonstrates a cystic mass containing echogenic fluid. MRI can be employed where a congenital malformation such as vaginal agenesis is suspected (6).

Surgical hymenectomy is the routine management for this condition, with few long-term complications (3,5). Untreated, imperforate hymen may cause retrograde menstruation and subsequent endometriosis, infection, or hydronephrosis and renal failure (1,7). It is therefore important that this diagnosis is promptly recognised.

In conclusion, imperforate hymen is a rare condition which can present as painless acute urinary retention. Its diagnosis is often delayed due to its low incidence and insufficient examination of the patient (1). Physical examination of the genital tract must always be considered for all patients where imperforate hymen is suspected and may avoid unnecessary radiological investigation.

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Potential Conflicts of Interest: All authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.