Imperforate hymen presenting as vaginal cyst in a 16-month-old child – considerations for an early diagnosis

Introduction

Imperforate hymen (IH) is a congenital anomaly of the female external genitalia, most often diagnosed in puberty. IH is found when perforation fails to occur during embryonic development or perinatal period. ¹ The clinical pictures vary from abdominal, low back pain, vaginal cyst to acute urinary retention. In infants, IH is detected as an incidental finding, while in adolescents, it is revealed during the evaluation of primary amenorrhea. ² The aim of this report is to emphasise the necessity of a thorough examination of genitalia in female newborns.

Patient presentation

A 16-month-old female infant was brought to paediatrician by the mother due to redness of the genitalia and minor oedema observed at the vaginal ostium when the baby was crying. The paediatrician made the diagnosis of vulvitis. Two months later, the mother brought the child to the paediatrician again, emphasising the same symptomatology, and the child was referred to a gynaecologist. Inspection of the child's genitalia revealed a whitish cystic growth and examination in narcosis was scheduled for suspicion of vaginal cyst. At the beginning of examination in narcosis, neither the vagina nor the cystic growth was visible. Cystic growth was only visualised by digital rectal examination and external suprapubic pressure (Figure 1). OPEN IN VIEWER

As uterus was not palpated on digital rectal examination, the Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome was suspected. Abdominal ultrasonography showed normal finding of abdominal organs and kidneys, both ovaries with minor cysts, but uterus was not visualised. Magnetic resonance revealed infantile uterus, ovaries with follicular cysts and a small amount of fluid in the vagina (Figure 2). Skeletal x-ray and ultrasonography of the heart was normal. Cytogenetic analysis of chromosomes yielded normal female karyotype. Hormonal status was normal. The value of antimüllerian hormone was within the normal limits for the child’s age. In WNT4 gene, no mutation was detected. The diagnosis of IH was made. Since the child was free from discomforts, surgical intervention was abandoned with gynaecologic follow-up recommended before puberty or earlier if needed. OPEN IN VIEWER

Discussion

Hymen is a solid membrane between the proximal uterovaginal tract and the introitus. Imperforate hymen is found when perforation fails to occur during embryonal development or perinatal period. ¹ The diagnosis is mostly made in puberty, having been unrecognisable before due to the absence of symptoms and incomplete paediatric examination. ³ Early detection is of utmost importance because it may indicate some anomalies, e.g. vaginal agenesis known as the MRKH syndrome, vaginal cyst, urethral diverticulum, ectopic ureter, etc. ⁴ In the sixth week of embryonic development, both male and female embryos have two sets of paired ducts: Müllerian ducts, from which parts of the female reproductive system (uterine tube, uterus, uterine cervix, and two-thirds of vagina) develop; and Wolffian ducts developing into parts of the male reproductive system. The inferior part of the vagina develops from the urogenital sinus, and the ovaries from germinal cells. ⁵ The anomaly known as the MRKH syndrome is characterised by the complete absence of the uterus, superior two-thirds of the vagina and both uterine tubes. The inferior third of the vagina form a short, dead-end recess in the perineum. External genitalia show normal development. Development and function of the ovaries are preserved since they originate from primitive mesoderm. ⁶ Ovaries are usually polycystic. This form of anomaly is found in MRKH syndrome type I. MRKH syndrome type II is associated with anomalies of the kidneys, spine, auditory apparatus and heart. This form is also called GRES (genital, renal, ear, skeletal) syndrome. ⁷ Suspicion of anomalies in Müllerian duct development is raised by various types of clinical symptomatology. In infants, a palpable mass in the abdomen, pelvis or vagina can be the first sign, in adolescents delayed menarche and in women of reproductive age the infertility. The cause of these anomalies has not yet been fully identified. Currently, however, a hypothesis on the genetic cause has been increasingly advocated. The syndrome seems to be transmitted as an autosomal dominant trait of variable intensity. ⁸ According to literature data, the WNT4 gene appears to be most widely associated with anomalies in the formation of the female reproductive system. Its role in the regulation of cellular and tissue growth and differentiation during embryogenesis has been demonstrated, ⁹ although it is still a matter of debate whether or not a WNT4 gene mutation is responsible for the MRKH syndrome. Skene’s duct cyst is another differential diagnostic entity because ducts are located immediately behind the vaginal ostium and the urethra. However, note should be made of the presence of vaginal patency as the main fact. Unlike IH in an infant, this condition requires surgical intervention. ¹⁰

Conclusion

Imperforate hymen is a congenital anomaly of female external genitalia.