A full-term, female infant was delivered via spontaneous vaginal delivery. Although the mother received no prenatal care, the labor and delivery were unremarkable. The initial physical examination revealed a 1.5-cm mass in the infant's vagina (see accompanying figure). The mass was soft, pearly in color, and well vascularized. The infant had no facial or extremity defects, no heart murmurs, and no abdominal or pelvic masses. The lung examination was unremarkable. The infant had mild jaundice secondary to ABO blood type incompatibility, which resolved without therapy. She was able to bottle feed successfully, and had normal urination and bowel movements.
Ultrasonography of the kidneys was normal with no evidence of hydronephrosis. Ultrasonography of the pelvis was also normal with no dilation of the vagina or uterus.
The answer is D: imperforate hymen. Imperforate hymen is the most common obstructive anomaly of the female genital tract, occurring in approximately 0.1 percent of female newborns.1 The condition occurs when the layer of epithelialized tissue that forms the hymen completely obstructs the vaginal introitus. Familial occurrences have been reported, but most cases are isolated. Some cases have been reported secondary to sexual abuse.2
The presentation of imperforate hymen varies widely. If there is no distension of the uterus or vagina secondary to estrogen-related secretions at birth, the condition may remain undiagnosed until puberty. On the other hand, the increased pressure may cause obstruction of the urinary tract, leading to hydronephrosis.3,4 Undiagnosed or misdiagnosed imperforate hymen has led to significant morbidity and mortality, including laparotomy for suspected malignancy, respiratory failure secondary to abdominal distension, and bowel perforation.5 Some studies have demonstrated that delayed treatment can lead to sexual difficulties, menstrual irregularities, and infertility.6 Rarely, prenatal ultrasonography identifies hydrocolpos or hydrometrocolpos in the fetus.7 Imperforate hymen is treated surgically with hymenotomy.
Bardet-Biedl syndrome is a rare, genetically heterogenous group of disorders characterized by retinitis pigmentosa, postaxial polydactyly, endocrine anomalies, nephropathy, and mental impairment. Retinitis pigmentosa is the hallmark of Bardet-Biedl syndrome. Besides visual disturbances, the presentation is highly variable. Associated endocrine anomalies include diabetes mellitus (50 percent), obesity (90 percent), male hypogonadism (88 percent), and menstrual irregularities (100 percent).8
Hematocolpos, or hematometrocolpos, is often diagnosed during puberty when a patient presents with abdominal pain and primary amenorrhea. The condition occurs when menstruation causes vaginal or uterine dilatation. Hematocolpos sometimes presents as a purple vaginal mass, but it is rarely noted in newborns.
Hydrometrocolpos occurs when secretions produced by the uterine and vaginal mucosa at birth lead to distention of the vagina and uterus. Hydrocolpos involves only the vagina. Both conditions are diagnosed when dilatation is noted on pelvic ultrasonography.
McKusick-Kaufman syndrome, or hydrometrocolpos-polydactyly syndrome, is a rare, autosomal recessive syndrome. The condition is characterized by hydrometrocolpos (80 to 95 percent), postaxial polydactyly (90 percent), and congenital heart defects (10 to 20 percent).4,8 Because of the overlap between this syndrome and Bardet-Biedl syndrome, genetic counseling is required to ensure accurate diagnosis.
|Bardet-Biedl syndrome||Retinitis pigmentosa, postaxial polydactyly, endocrine anomalies, nephropathy, mental impairment|
|Imperforate hymen||Complete obstruction of the vaginal introitus by the epithelialized tissue that forms the hymen; varied presentation|
|Hematocolpos||Distension of vagina or uterus secondary to menstrual blood accumulation; most common in pubertal girls with primary amenorrhea and abdominal pain; purple vaginal mass may be present|
|Hydrometrocolpos||Distension of vagina (hydrocolpos) and uterus caused by obstruction of the drainage of genital secretions; pelvic ultrasonography shows dilatation|
|McKusick-Kaufman syndrome||Hydrometrocolpos, postaxial polydactyly, congenital heart defects|