A 34-year-old woman comes to the office for evaluation of 3 months of amenorrhea. She first began experiencing irregular periods a year ago, and now they have stopped completely. The patient has no headaches, visual changes, galactorrhea, hair loss, or fatigue. She has a history of non-Hodgkin lymphoma for which she received chemotherapy 5 years ago; there are no signs of recurrence. The patient currently takes no medications. Family history is noncontributory. Her most recent Pap test was last year and all prior testing was normal. She has no history of sexually transmitted infections. The patient does not use tobacco, alcohol, or illicit drugs. Blood pressure is 120/80 mm Hg and pulse is 78/min. BMI is 28 kg/m². Physical examination reveals a nonenlarged thyroid without masses. Cardiopulmonary examination is normal. Pelvic examination reveals dry vaginal mucosa and a small, anteverted, mobile uterus with no adnexal masses. A pregnancy test is negative. Which of the following laboratory findings are most likely present in this patient?

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11ec25c8_d99d_62e2_bc81_331bb86d6669_MD0003_00 This patient has a history of cancer, amenorrhea, and signs of estrogen deficiency (eg, vaginal dryness), consistent with ovarian failure secondary to chemotherapy. Hypergonadotropic hypogonadism in women age <40, also known as primary ovarian insufficiency, occurs due to the absence of developing follicles. Chemotherapy and radiation target rapidly dividing cancer cells but also affect the proliferating granulosa and theca cells of the ovary. Patients undergoing cancer treatment often have transient amenorrhea but have an overall shortened reproductive capacity even if menses return. Ovarian failure results in decreased estrogen, thereby decreasing negative feedback to the hypothalamus and pituitary and resulting in increased FSH and LH production. Treatment with hormone replacement therapy provides menopausal symptom relief and bone loss protection. Fertility preservation may be possible with cryopreservation techniques. (Choice B) Functional hypothalamic amenorrhea occurs in patients with relative caloric deficiency (unlikely with a normal BMI) and is characterized by a decrease in GnRH secretion, resulting in decreased FSH and LH levels and suppression of ovarian function. There is no association with chemotherapy. (Choice C) Asherman syndrome is a structural cause of secondary amenorrhea due to intrauterine adhesions from endometrial infection (eg, endometritis) or instrumentation (eg, dilation and curettage). Hormone levels are normal. (Choice D) Prolactinoma is a cause of secondary amenorrhea; elevated prolactin levels negatively inhibit hypothalamic GnRH secretion and result in decreased FSH and LH levels. Symptoms include headache, bilateral hemianopsia, and galactorrhea, which are not seen in this patient. In addition, there is no correlation with history of chemotherapy. (Choice E) Hypothyroidism can present with menstrual dysfunction, fatigue, and hair changes, without signs of hypoestrogenism. Findings include an enlarged thyroid, elevated TSH, and low T3/T4 levels. In hypothyroidism, low T3/T4 increases thyrotropin-releasing hormone (TRH) secretion from the hypothalamus. Increased TRH stimulates prolactin secretion, which has inhibitory effects on GnRH production, thereby decreasing FSH and LH levels. Educational objective: Ovarian failure may occur secondary to chemotherapy and presents with amenorrhea and signs of estrogen deficiency (eg, vaginal dryness). Ovarian failure is characterized by increased FSH and LH due to lack of feedback inhibition from estrogen. References: Hormone replacement therapy in young women with primary ovarian insufficiency and early menopause. (http://www.ncbi.nlm.nih.gov/pubmed/27912889)

A 34-Year-Old Woman Comes to the Office for Evaluation of 3