Volume 4, Case 8
Brunhild Halm, M.D.
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
This is a 13 year old female who presents to the E.D. with a one day history of increasing intermittent RLQ pain and the complaint of feeling "full". She describes the pain as sharp and stabbing without radiation. Standing, running, and deep breathing make it worse. There is no history of vomiting, diarrhea, or fever. She denies urgency, frequency, or burning on urination. She has had similar pain of less severity for the last two years, especially when running. She has never had a menstrual period and denies being sexually active.
She was born in Vietnam and moved to the U.S. two years ago. Her PMH is negative. Medications: None. Immunizations are UTD.
Exam: VS T 38.8, P 118, R 24, BP 108/69. She is awake, alert, cooperative, and in no distress. Oral mucosa moist. Heart regular, no murmurs. Lungs clear. Abdomen non-distended. There is mild to moderate tenderness in both lower quadrants and in the suprapubic area, but no rebound tenderness or guarding. There are no palpable masses. Bowel sounds are active. Tanner Stage: Breasts IV, Pubic hair IV. Color and perfusion are good. Extremities unremarkable.
Laboratory studies:
CBC WBC 15,500, 76% segs, 12% bands, 3% lymphs, 9% monos. Hgb 12.8, Hct 39.1. Platelet count 265,000. Chemistry panel normal. Urinalysis normal. Urine HCG negative.
What is your diagnosis at this point?
An adolescent female presents with a long-standing history of intermittent abdominal pain that acutely worsens. She has well-developed secondary sex characteristics but has not reached menarche. This makes an obstruction of the genital tract likely.
Obstruction of the genital tract results in the accumulation of secretions, blood, or both within the uterus, vagina, or both, depending on the level of obstruction. The three main types of congenital vaginal obstructions are:
1. Segmental atresia, usually midvagina.
2. Transverse vaginal septum, most common in the midportion.
3. Imperforate hymen.
View diagram of these types.
The vagina proximally, and often the uterus are dilated, resulting in hydro(metro)colpos at birth or hemato(metro)colpos at puberty. Examination of the genitalia in our patient reveals a thick, tense, bulging hymen at the introitus, which establishes the diagnosis of imperforate hymen. On rectal exam a midline mass is palpable anteriorly.
A pelvic ultrasound is performed.
View pelvic ultrasound.
The sagittal view or long axis of the uterus (shown above) and transverse view (shown below) shows marked distention of the endometrial cavity, compressing the bladder anteriorly. Scattered internal echoes represent blood, and mucous debris. The uterus is enlarged (14.9 cm by 8.3 cm by 6.3 cm).
View labeling on ultrasound.
The uterine cavity is labeled as "U". The bladder (labeled "B") is compressed. The anterior abdominal wall musculature is labeled as "M". The crosses mark the boundaries of the uterus.
Contrast this with an ultrasound of the normal post pubertal uterus.
View normal pelvic ultrasound.
The sagittal view is shown above. The transverse view is shown below. The maximum dimensions of the nulliparous uterus are approximately 8cm in length by 5cm in width by 4cm in AP diameter. The normal endometrial cavity is seen as a thin echogenic line as a result of reflection from the interface between the opposing surfaces of the endometrium.
View labeling on this normal ultrasound.
The bladder (labeled "B") is dilated and fluid-filled in both views to optimize the transmission of ultrasound from the anterior pelvis. The sagittal view (above) shows the myometrial wall labeled as "U". The thin echogenic (white) line above the "U" represents the endometrial cavity with the opposing myometrium above this. In the transverse view (below), the myometrium is labeled as "U". The echogenic endometrial cavity is just above the letter "U" with the opposing myometrial wall above this. The crosses mark the outer dimensions of the uterus in both views.
Our patient is taken to the operating room. A hymenectomy is performed, which allows the accumulated menstrual blood and vaginal secretions to drain.
An imperforate hymen is a rare lesion, but it is the most common truly obstructive abnormality of the genital tract. In one survey, it occurred in 0.1% of full term female neonates. In imperforate hymen, the vagina is obliterated by a thick membrane interpreted as hymen, since no hymen remnants are identified.
Some patients may present at birth with a large midline mass due to accumulation of vaginal secretions secondary to stimulation by maternal hormones. The uterus and fallopian tubes may also be dilated (hydrometrocolpos). In the presence of neonatal withdrawal bleed, a hematocolpos may develop, which presents as a dark purplish bulge at the introitus. Most patients are asymptomatic at birth and during childhood, but present in late puberty with primary amenorrhea, cyclical crampy abdominal pain, and a pelvic mass due to accumulation of menstrual blood.
An imperforate hymen is not of Mullerian origin; therefore it is not associated with other genitourinary abnormalities. However, hematocolpos or hydrocolpos may lead to complete urethral obstruction or variable degrees of hydroureter or hydronephrosis as a result of the chronic extrinsic pressure. Patients with imperforate hymen associated with hematocolpos also have an increased risk of endometriosis, which is felt to be secondary to the mechanical obstruction and metaplasia. If this retrograde flow is stopped early enough, endometriosis might be prevented. Therefore, surgery should be scheduled promptly for adolescents, but can be delayed and performed electively for asymptomatic infants and children.
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