Review Question - QID 218743

This 14-year-old patient who has not yet undergone menarche and has no secondary sexual characteristics (Tanner stage 1 breasts and pubic hair) requires evaluation for primary amenorrhea. Initial workup should include a thorough history and physical examination, pelvic ultrasound, serum beta-hCG levels, and follicle-stimulating hormone (FSH) levels.

Primary amenorrhea is defined by the absence of menarche by age 15 years in patients with secondary sexual characteristics, or by age 13 years in patients without secondary sexual characteristics. The initial evaluation of primary amenorrhea should include a thorough history and physical examination to determine if the uterus is present. Pelvic ultrasound can also be used to further evaluate the presence of the ovaries, uterus, and cervix, as well as other anatomic abnormalities of the reproductive tract. Initial laboratory testing should include serum beta-hCG levels, TSH, PRL, and FSH levels. Especially in patients without secondary sexual characteristics but with a uterus, FSH levels can help distinguish gonadal from central hypothalamic-pituitary disorders. The treatment of primary amenorrhea varies depending on the underlying etiology.

Yoon and Cheon reviewed the evaluation and management of amenorrhea associated with congenital sex hormonal disorders. The authors note that the management of primary amenorrhea varies considerably depending on etiology. The authors recommend that patients without secondary sexual characteristics and primary amenorrhea at age 13 should undergo measurement of FSH levels.

Incorrect Answers:
Answer 1: An adrenocorticotropic hormone (ACTH) stimulation test is useful in the evaluation of 17-alpha-hydroxylase deficiency, a potential etiology of primary amenorrhea. However, this test should only be performed in patients in which the FSH level is high and there are features of 17-alpha-hydroxylase deficiency (hypertension and minimal body hair).

Answer 3: Luteinizing hormone (LH) level is useful for evaluating the etiology of primary amenorrhea in patients without secondary sexual characteristics and a low FSH. A low LH suggests hypogonadotropic hypogonadism or hypothalamic-pituitary disorders.

Answer 4: Karyotyping should be performed in cases of primary amenorrhea in which there is a lack of secondary sexual characteristics and the FSH level is high. This can help distinguish between primary ovarian insufficiency (46,XX), gonadal dysgenesis (46,XY), and Turner syndrome (45,X).

Answer 5: Pituitary magnetic resonance imaging (MRI) can be used to evaluate sellar masses causing primary amenorrhea. Due to the high cost of this test, it should only be performed after laboratory testing for low FSH and LH in patients with primary amenorrhea.

Bullet Summary:
In patients with primary amenorrhea and a lack of secondary sexual characteristics, the next best step in management is assessing levels of follicle-stimulating hormone (FSH).