Nasopharyngeal carcinoma spreading along the eustachian tube: the imaging appearance

Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly, laterally, posteriorly, superiorly and inferiorly. Skull base invasion is the common presentation, in up to one-third of cases. We report a rare spreading pathway of NPC, via the eustachian tube. A 44-year-old male suffered from NPC and got radiotherapy about 2 years ago. He suffered from middle ear effusion and facial nerve palsy on the right side recently. The computed tomography and magnetic resonance image could clearly depict the infiltrating tumor over the mastoid region and tympanic cavity on the right side, spreading along the eustachian tube. It could result in eustachian tube dysfunction and middle ear effusion. The nature of the right facial palsy was most likely due to tumor infiltration.