This week, we are sharing another USMLE® Step 1-style practice question to test your knowledge of medical topics. Today’s case involves a 22-year-old woman who was diagnosed with herpes simplex genital infection two months ago. Speculum examination reveals mucopurulent discharge and a friable erythematous cervix. Cervical motion tenderness is absent. Which of the following findings is most likely on laboratory evaluation? Can you figure it out?
A 22-year-old woman comes to her primary care physician’s clinic for evaluation of one week of burning urination, increased urinary frequency, and spotting after sexual intercourse. She was diagnosed with herpes simplex genital infection two months ago. She is sexually active with one male partner and uses condoms inconsistently. Temperature is 37.0°C (98.6°F), pulse is 90/min, respirations are 20/min, and blood pressure is 120/75 mmHg. On physical exam, the abdomen is soft and nontender. External genital examination reveals three healed, nontender genital ulcers. Speculum examination reveals mucopurulent discharge and a friable erythematous cervix. Cervical motion tenderness is absent. Which of the following findings is most likely on laboratory evaluation?
A. Diplococci within polymorphonuclear leukocytesB. Positive hepatitis B surface antigen
C. Multinucleated cells on Tzanck smear
D. Spirochetes on dark field microscopy
E. Gram-negative rods in a “school of fish” chain
Scroll down to find the answer!
The correct answer to today’s USMLE® Step 1 Question is…
A. Diplococci within polymorphonuclear leukocytes
Before we get to the Main Explanation, let’s look at the incorrect answer explanations. Skip to the bottom if you want to see the correct answer right away!
Incorrect answer explanations
The incorrect answers to today’s USMLE® Step 1 Question are…
B. Positive hepatitis B surface antigen
Incorrect: Hepatitis B antigen is diagnostic of hepatitis B infection. Most patients are asymptomatic or present with a febrile illness and icterus. This patient’s presentation is more consistent with acute cervicitis.
C. Multinucleated cells on Tzanck smear
Incorrect: Herpes simplex virus can be diagnosed by performing a Tzanck smear, which will demonstrate the presence of multinucleated cells. Most patients present with painful genital ulcers, dysuria, and tender lymphadenopathy. This patient does not have evidence of an active HSV-2 infection.
D. Spirochetes on dark field microscopy
Incorrect: Darkfield microscopy is used to diagnose syphilis. Primary syphilis typically presents with a single nontender genital chancre. This patient’s presentation with vaginal discharge, spotting, and dysuria is more consistent with acute cervicitis secondary to Neisseria gonorrhea or Chlamydia trachomatis.
E. Gram-negative rods in a “school of fish” chain
Incorrect: Haemophilus ducreyi presents with painful genital ulcers and suppurative lymphadenopathy. Gram stain reveals gram-negative rods with a “school of fish” appearance. This patient’s presentation is more consistent with acute cervicitis secondary to Neisseria gonorrhea or Chlamydia trachomatis.

Main Explanation
This patient presents with vaginal discharge, spotting, dysuria, and a friable, erythematous cervix on clinical examination–suggestive of acute cervicitis. The most common causes of acute cervicitis include Neisseria gonorrhea and Chlamydia trachomatis.
In patients with female genitalia, infection with Neisseria gonorrhea presents with purulent or mucopurulent cervical discharge and/or vaginal bleeding. Physical examination findings include a friable, erythematous cervix with copious purulent discharge. Diagnostic studies include a gram stain and culture of vaginal fluid or an endocervical sample with microscopy and culture. A gram stain will demonstrate gram-negative diplococci within polymorphonuclear leukocytes.
NAAT (nucleic acid amplification test) is indicated in the diagnostic evaluation of acute cervicitis to evaluate for the presence of both Neisseria gonorrhea and Chlamydia trachomatis, which cannot be detected with traditional gram stain and culture. The presentation of cervicitis due to Neisseria gonorrhea is similar to that caused by Chlamydia trachomatis, although gonorrhea involvement is more likely to cause purulent or mucopurulent discharge. Because coinfection with the two pathogens is common, symptomatic patients are empirically treated for both with intramuscular ceftriaxone and a macrolide or tetracycline (doxycycline).
Meanwhile, in patients with male genitalia, infection with Neisseria gonorrhoeae results in urethritis and copious urethral discharge. Patients may have additional symptoms of dysuria, increased urinary frequency, and pruritus. Diagnostic workup similarly involves gram stain, culture and NAAT evaluation of a urethral sample.
Major Takeaway
Neisseria gonorrhoeae can cause urethritis in patients with male genitalia and acute cervicitis in patients with female genitalia. Diagnostic evaluation may detect the presence of gram-negative diplococci within polymorphonuclear lymphocytes. NAAT (nucleic acid amplification test) testing is the diagnostic test of choice for both Neisseria gonorrhea and Chlamydia trachomatis infections, which often occur simultaneously.
References
McCormack WM, Stumacher RJ, Johnson K, Donner A. Clinical spectrum of gonococcal infection in women. Lancet. 1977 Jun 4;1(8023):1182-5. doi: 10.1016/s0140-6736(77)92720-9. PMID: 68279.
Barlow D, Phillips I. Gonorrhoea in women. Diagnostic, clinical, and laboratory aspects. Lancet. 1978 Apr 8;1(8067):761-4. doi: 10.1016/s0140-6736(78)90870-x. PMID: 76760.
Platt R, Rice PA, McCormack WM. Risk of acquiring gonorrhea and prevalence of abnormal adnexal findings among women recently exposed to gonorrhea. JAMA. 1983 Dec 16;250(23):3205-9. PMID: 6417362. _________________________
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