A 26-year-old woman presents to the clinic with a 9-month history of absent menses. Over t… — USMLE Step 2 CK

A 26-year-old woman presents to the clinic with a 9-month history of absent menses. Over the past 6 months, she has noticed a rapid increase in thick, dark hair on her face and chest, temporal hair thinning, and a noticeable deepening of her voice. She had menarche at age 12, and her menstrual cycles were previously regular, occurring every 28 days. She takes no medications and is not sexually active. Her body mass index is $23 \text{ kg/m}^2$ . Vital signs are within normal limits. Physical examination reveals severe nodulocystic acne over the face and back, temporal balding, and notable clitoromegaly. A urine pregnancy test is negative. Serum thyroid-stimulating hormone and prolactin levels are within normal limits. Which of the following is the most appropriate next step in evaluation?

Measurement of serum testosterone and dehydroepiandrosterone sulfateAnswer
B
Initiation of combined oral contraceptive pills
C
Endometrial biopsy
D
Measurement of serum free thyroxine
E
Reassurance and scheduled clinical observation

Answer

Measurement of serum testosterone and dehydroepiandrosterone sulfate

The correct next step is to measure serum testosterone and DHEAS. This patient presents with rapid-onset hirsutism, amenorrhea, and severe virilization (clitoromegaly, deepening voice, male-pattern balding). Unlike Polycystic Ovary Syndrome (PCOS), which causes slowly progressive hirsutism, rapid virilization is a red flag for an androgen-secreting tumor. Markedly elevated testosterone points to an ovarian source (e.g., Sertoli-Leydig cell tumor), whereas markedly elevated DHEAS points to an adrenal source.

Step-by-Step Solution

Analyze the clinical presentation of rapid-onset hirsutism, amenorrhea, and signs of virilization (clitoromegaly, voice deepening).

The presence of virilization and its rapid onset over 6 months indicate markedly elevated androgen levels, highly suspicious for an androgen-secreting neoplasm rather than a benign condition.

Differentiating between slowly progressive hirsutism (typical of PCOS) and rapid virilization (typical of tumors) is critical for determining urgency and appropriate workup.

Determine the most appropriate diagnostic test to locate the source of the excess androgens.

Testosterone is primarily secreted by the ovaries, while DHEAS is primarily secreted by the adrenal glands.

Identifying whether the excess androgens are of ovarian or adrenal origin will guide subsequent imaging (pelvic ultrasound vs. abdominal CT).

Select the intervention that measures these specific endocrine markers.

Measurement of serum testosterone and dehydroepiandrosterone sulfate (DHEAS) is the indicated next step.

This establishes the diagnosis and localizes the source of the suspected tumor before initiating any symptomatic treatment.

Key Concept

Evaluation of rapid-onset virilization requires immediate measurement of serum testosterone and DHEAS to rule out an androgen-secreting tumor of the ovary or adrenal gland.

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