External auditory canal involvement by nasopharyngeal carcinoma via eustachian tube spread: A case report.

We present the imaging findings of a 44-year-old female patient who was diagnosed with nasopharyngeal carcinoma (NPC) extending from the nasopharynx to the external auditory canal (EAC) through the Eustachian tube (ET). The patient presented with a left neck submandibular lump on initial presentation that showed NPC upon fine needle aspiration, leading to chemoradiotherapy. Despite treatment, the patient experienced multiple relapses and later presented with aural symptoms, including left ear pain, foul-smelling drainage, and trismus on recurrence, and was subsequently diagnosed through biopsy. CT, MRI, and PET-CT scans revealed an extensive infiltrative nasopharyngeal mass extending into the left ET, involving the EAC. This rare case highlights the importance of considering the extension of NPC into the EAC as a potential etiology in patients who present with aural symptoms.