This week, we are sharing another USMLE® Step 1-style practice question to test your knowledge of medical topics. Today’s case focuses on a 51-year-old woman who comes to the clinic for an assessment of a tongue lesion. Her history is significant for active IV drug use and homelessness. She was recently hospitalized and treated for Pneumocystis pneumonia six months ago. Oral examination reveals a white lesion on the lateral margin of the tongue with “feathery” projections. The lesion is not easily scraped away with a tongue depressor. The pathogen implicated in this patient’s tongue lesion is also associated with which of the following diseases? Can you figure it out?
A 51-year-old woman comes to the clinic for an assessment of a tongue lesion. She states it is occasionally painful and has impacted her ability to eat. Her history is significant for active IV drug use and homelessness. She was recently hospitalized and treated for Pneumocystis pneumonia six months ago. She takes no medications and has not visited a primary care physician in over ten years. Vitals are within normal limits. Physical examination reveals a thin woman with temporal wasting and minimal muscle mass. Oral examination reveals a white lesion on the lateral margin of the tongue with “feathery” projections. The lesion is not easily scraped away with a tongue depressor. There are track marks and scars present in the bilateral antecubital fossa. The rest of the physical examination is noncontributory. The pathogen implicated in this patient’s tongue lesion is also associated with which of the following diseases?
A. Kaposi sarcoma
B. Shingles
C. Burkitt lymphoma
D. Cervical cancer
E. Vulvovaginitis
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The correct answer to today’s USMLE® Step 1 Question is…
C. Burkitt lymphoma
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…
A. Kaposi sarcoma
Incorrect: Kaposi sarcoma is caused by human herpesvirus-8 (HHV-8). Kaposi sarcoma presents with multiple cutaneous lesions (vascular tumors) and is almost exclusively seen in AIDS patients. A different pathogen precipitates this patient’s condition (hairy leukoplakia).
B. Shingles
Incorrect: Shingles is caused by reactivation of a prior infection with varicella-zoster virus (VZV) (i.e. chickenpox). A different pathogen causes this patient’s condition (hairy leukoplakia).
D. Cervical cancer
Incorrect: Cervical cancer is caused by the human papillomavirus (HPV). HPV preferentially infects squamous cells and can result in oropharyngeal cancers. However, this patient’s hairy leukoplakia is caused by a different virus.
E. Vulvovaginitis
Incorrect: Vulvovaginitis occurs secondary to colonization with various pathogens, with one of the most common pathogens being Candida albicans. Oropharyngeal candidiasis, also known as oral thrush, is caused by C. albicans. A physical examination will reveal white plaques on the oral mucosa, similar to this patient. However, oral thrush is scrapable with a tongue depressor, unlike leukoplakia and erythroplakia (premalignant lesions).
Main Explanation
Oral hairy leukoplakia (OHL) is an Epstein-Barr virus (EBV)-mediated mucocutaneous condition involving the squamous epithelium of the tongue. Hairy leukoplakia is associated with HIV infection or immunosuppression – as suggested in this vignette by the patient’s history of IV drug use and recent hospitalization with PCP pneumonia. The pathophysiology of OHL depends on several factors, including EBV virulence/strain and host immune system factors.
The lateral border of the tongue is more susceptible to mechanical trauma, predisposing epidermal cells at this location to infection with EBV. Hence, this condition is commonly discovered as a unilateral non-painful white lesion on the lateral margin of the tongue. The lesion may vary in appearance as either a smooth and flat or irregular, “hairy” or “feathery” lesion with prominent folds or projections. In contrast to oral thrush, OHL lesions are adherent to the surface and cannot be removed by scraping. The surrounding tissue does not typically demonstrate any signs of erythematous change. EBV is implicated in several conditions beyond OHL, such as infectious mononucleosis, Burkitt lymphoma, and nasopharyngeal carcinoma.
Major Takeaway
Oral hairy leukoplakia (OHL) is an Epstein-Barr virus (EBV)-a mediated mucocutaneous condition in which the virus infects the squamous epithelium of the tongue. Unlike oral thrush, lesions are adherent to the surface and cannot be removed via scraping.
References
Rathee M, Jain P. Hairy Leukoplakia. [Updated 2020 Apr 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554591/
Khammissa RA, Fourie J, Chandran R, Lemmer J, Feller L. Epstein-Barr Virus and Its Association with Oral Hairy Leukoplakia: A Short Review. Int J Dent. 2016;2016:4941783. doi: 10.1155/2016/4941783. Epub 2016 Mar 7. PMID: 27047546; PMCID: PMC4800082._________________________
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The United States Medical Licensing Examination (USMLE®) is a joint program of the Federation of State Medical Boards (FSMB®) and National Board of Medical Examiners (NBME®). Osmosis is not affiliated with NBME nor FSMB.
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