Nasopharyngeal carcinoma masked by contralateral otitis media and misleading magnetic resonance imaging: a diagnostic pitfall case report

Nasopharyngeal carcinoma may initially present with otologic symptoms. When the laterality of otologic symptoms is discordant with that of a nasopharyngeal lesion and magnetic resonance imaging (MRI) gives a benign-appearing impression, clinical judgment may be misled. A 62-year-old Han Chinese man presented with a 5-day history of left aural fullness after an upper respiratory tract infection and was initially treated for presumed left otitis media with effusion. Three days later, because the symptoms persisted, otoendoscopy and rigid nasal endoscopy were performed. Otoendoscopy showed persistent left middle ear effusion, whereas rigid nasal endoscopy revealed an elevated lesion approximately 1 cm in size on the right posterior-superior wall of the nasopharynx near the pharyngeal recess, with a smooth mucus-covered surface. Contrast-enhanced MRI favored an inflammatory lesion with a small retention cyst or a small inflammatory polypoid lesion; however, endoscopic biopsy confirmed poorly differentiated non-keratinizing nasopharyngeal carcinoma. Plasma Epstein–Barr virus (EBV) DNA was 2.54 × 10 3 copies/mL, EBV viral capsid antigen immunoglobulin G was > 750 U/mL, and EBV viral capsid antigen immunoglobulin M was negative. After multidisciplinary review, the disease was staged as cT1N1M0, stage II. The patient received three cycles of induction gemcitabine plus cisplatin followed by intensity-modulated radiotherapy with concurrent weekly cisplatin. Follow-up nasal endoscopy and contrast-enhanced MRI showed interval shrinkage of the nasopharyngeal lesion. This case highlights a diagnostic pitfall in which contralateral otologic symptoms and a benign-appearing MRI impression masked nasopharyngeal carcinoma. In adults with persistent unilateral middle ear effusion, the possibility of nasopharyngeal malignancy should still be considered even when symptom laterality is discordant and MRI appears non-neoplastic. If nasal endoscopy reveals an abnormal nasopharyngeal lesion, prompt histopathological confirmation is warranted.