A 15-year-old girl comes to the office because her menses have not started. She feels embarrassed because her friends have been "developing" and she looks younger than her peers. The patient has no headaches, visual changes, abdominal pain, or behavior changes. Her mother and maternal grandmother began menstruating around age 13. The patient is not sexually active and is not on contraception. Height is

Question

A 15-year-old girl comes to the office because her menses have not started.  She feels embarrassed because her friends have been "developing" and she looks younger than her peers.  The patient has no headaches, visual changes, abdominal pain, or behavior changes.  Her mother and maternal grandmother began menstruating around age 13.  The patient is not sexually active and is not on contraception.  Height is <3rd percentile and weight is at the 20th percentile.  Vital signs are normal.  Physical examination shows no breast development, normal external female genitalia, and Tanner stage 1 pubic hair development.  Urine β-hCG is negative. 
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d670_6616_bc81_67a225893186_MD0003_00 Primary amenorrhea is the absence of menarche at age ≥13 in girls with no secondary sexual characteristics (eg, breast development). In those with secondary sexual characteristics, primary amenorrhea is absence of menarche at age ≥15. Amenorrhea can result from either functional or anatomic problems of the hypothalamus, pituitary gland, ovaries, uterus, or vagina. Therefore, the first step in management is to evaluate the female reproductive tract with a pelvic ultrasound to exclude anatomic abnormalities of the ovaries, uterus, or vagina. (Choices A and F) Testing of 17-hydroxyprogesterone and TSH levels evaluates for primary amenorrhea secondary to congenital adrenal hyperplasia and hypothyroidism, respectively. These tests may be indicated in patients with a uterus. congenital adrenal hyperplasia (Choice B) Brain MRI is performed in patients with a uterus and a low or inappropriately normal FSH (ie, rather than the elevated FSH seen with primary ovarian insufficiency) to evaluate for pituitary or hypothalamic tumors as a cause of amenorrhea. (Choice D) Reassurance and observation is appropriate for girls age <15 who have not undergone menarche but have other secondary sexual characteristics (ie, breast development). (Choice E) In patients without a uterus, karyotype and serum testosterone levels are ordered to evaluate for androgen insensitivity syndrome (46,XY and high testosterone) and Müllerian agenesis (46,XX and normal testosterone). Educational objective: Primary amenorrhea is the absence of menarche at age ≥15 in girls with secondary sexual characteristics (eg, breast development) or age ≥13 in girls without secondary sexual characteristics. The first step in management is a pelvic ultrasound to evaluate the female reproductive tract. References: Primary amenorrhea: diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/25336070)

A 15-Year-Old Girl Comes to the Office Because Her Menses