Review Question - QID 109439

This patient presents with primary amenorrhea in the setting of normal thelarche and pubarche. In light of her normal ultrasound and labs, as well as her ostensibly patent vagina on exam, a transverse vaginal septum is the most likely diagnosis.

Transverse vaginal septa typically occur in the upper part of the vagina, which may lead to a largely normal bimanual exam. Patients most commonly present with primary amenorrhea and cyclic abdominal pain, but the latter symptom may be absent. Because hormonal and organ function are intact, there is normal pubertal development, except for the absence of menarche.

Incorrect Answers:
Answer 1: Hypothalamic amenorrhea (HA) is a possible cause of amenorrhea, especially in competitive athletes. However, this patient’s body mass index is normal, and her FSH and estrogen are both normal. In HA, one would expect low FSH and low estrogen secondary to an increased CRH.

Answer 2: Hyperprolactinemia can cause amenorrhea by suppressing estrogen, and the most common cause is a prolactinoma. Although this patient endorses headaches, which can be sign of a prolactinoma, her description is more consistent with migraines, especially given her family history.

Answer 3: An imperforate hymen can cause a similar picture as a vaginal septum, with normal pubertal development except for the lack of menstruation. However, pelvic exam typically reveals hematocolpos, or a bulging membrane (the hymen) that blocks menstrual buildup from leaving the vagina.

Answer 5: Normal development typically includes thelarche by age 13 and menarche by age 15. Of note, the onset of thelarche should precede menarche by no more than two years.

Bullet Summary:
A transverse vaginal septum can cause primary amenorrhea with otherwise normal pubertal development.