A 34-year-old woman, who has never been pregnant, comes to the physician due to a 4-month … — USMLE Step 2 CK

A $34$ -year-old woman, who has never been pregnant, comes to the physician due to a $4$ -month history of rapidly progressing facial hair growth and severe acne. Her menstrual periods, previously regular every $28$ days, have completely stopped during this time. The patient has also noted that her voice sounds deeper than usual over the past few weeks. She has no significant past medical history and takes no medications. Her body mass index is $23 \text{ kg/m}^2$ . Vital signs show a blood pressure of $124/82 \text{ mmHg}$ and a heart rate of $76/\text{min}$ . Physical examination shows significant terminal hair growth on the chin, upper lip, and chest. Pelvic examination demonstrates clitoromegaly and normal vaginal rugae; bimanual examination reveals a normal-sized uterus, but the adnexa are difficult to palpate.

Laboratory studies show:
- $\beta$ -hCG: negative
- Prolactin: $14 \text{ ng/mL}$ (Normal: $< 20 \text{ ng/mL}$ )
- Thyroid-stimulating hormone: $2.2 \text{ } \mu\text{U/mL}$
- Total testosterone: $210 \text{ ng/dL}$ (Normal: $15-70 \text{ ng/dL}$ )
- Dehydroepiandrosterone sulfate (DHEAS): $2.5 \text{ } \mu\text{g/mL}$ (Normal: $0.5-4.0 \text{ } \mu\text{g/mL}$ )

Which of the following is the most appropriate next step in the evaluation of this patient?

Pelvic ultrasonographyAnswer
B
Abdominal computed tomography
C
Fasting serum 17-hydroxyprogesterone level
D
Initiation of combined oral contraceptives
E
Overnight 1-mg dexamethasone suppression test

Answer

Pelvic ultrasonography

This patient's rapid onset of frank virilization (clitoromegaly, deepening voice) combined with a markedly elevated serum testosterone level (

> 150 \text{ ng/dL}

) is highly suspicious for an androgen-secreting tumor. To localize the tumor, one must look at the specific androgen profile. In women, testosterone is primarily secreted by the ovaries, while dehydroepiandrosterone sulfate (DHEAS) is almost exclusively produced by the adrenal glands. Because this patient has a normal DHEAS level but extremely high testosterone, the excess androgen is of ovarian origin (e.g., a Sertoli-Leydig cell tumor). Therefore, the most appropriate next step is to evaluate the ovaries using pelvic ultrasonography.

Step-by-Step Solution

Identify the clinical syndrome from the patient's presentation.

The patient presents with rapid-onset (

4

months) virilization, evidenced by clitoromegaly and voice deepening, which is highly concerning for an androgen-secreting neoplasm.

Differentiating between benign hyperandrogenism (like PCOS, which is slow-onset and mild) and neoplastic hyperandrogenism (which is rapid and severe) dictates the urgency and direction of the workup.

Analyze the laboratory results to localize the source of excess androgens.

Total testosterone is markedly elevated (

210 \text{ ng/dL}

, typically

>150 \text{ ng/dL}

in tumors), while DHEAS is within normal limits.

Testosterone is primarily produced by the ovaries, whereas DHEAS is almost exclusively produced by the adrenal glands. This laboratory profile isolates the ovaries as the source of the hyperandrogenism.

Determine the next best diagnostic step based on the localized source.

Pelvic ultrasonography is chosen to visualize the ovaries and confirm the presence of a mass.

Since the labs point to an ovarian source (like a Sertoli-Leydig cell tumor), direct imaging of the pelvis is the most appropriate next step.

Key Concept

Patients with rapid-onset virilization and markedly elevated testosterone with normal DHEAS should undergo pelvic ultrasonography to evaluate for an ovarian androgen-secreting tumor.

Estimated Time:1m 15s

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