A 40-year-old man presents with a Sore Throat and unusual butterfly-shaped white plaques in his oropharynx. Explore the diagnostic journey for this rare finding.
A 40-year-old man was referred to the otorhinolaryngology clinic with a 1-month history of a sore throat. He reported no upper respiratory symptoms, fever, rash, or genital lesions. The physical examination was notable for nonulcerated white plaques that formed a butterfly shape across the posterior oropharynx, upper uvula, and tonsils. No lymphadenopathy or skin or genital lesions were present. Testing for the human immunodeficiency virus was negative. A biopsy of the plaques showed dense lymphoplasmacytic infiltration. Which of the following tests is most likely to reveal the diagnosis?
