Squamous Cell Carcinoma of the External Auditory Canal Presenting as a Persistent Ear Infection: A Case Report and Imaging Features.

Squamous cell carcinoma (SCC) is the most common malignant tumor involving the temporal bone but generally very rare. The temporomandibular joint (TMJ), middle cranial fossa, and facial nerve canal are uncommon areas for the tumor to spread. We present the case of primary SCC of the temporal bone in a 63-year-old male presenting for otorrhea, otalgia, facial weakness, and facial pain after failing outpatient antibiotic therapy for an ear infection. Initial inpatient workup was significant for a hypertensive emergency, leukocytosis, and acute kidney injury. Opacification of cavities (i.e., left middle ear, external auditory canal (EAC)), destructive bony changes (i.e., mastoiditis, erosion of facial nerve canal, and TMJ), and invasion of the middle cranial fossa due to a soft tissue mass were noted on CT and MRI. Operative biopsy showed moderately differentiated SCC. The patient received treatment at the hospital consisting of antibiotics and supportive treatment. Plans for an outpatient PET scan and chemoradiotherapy per consultants' recommendations were arranged. The patient was discharged with appropriate medications and outpatient referrals and underwent infuse-a-port placement. Overall, this case describes some key points given the limited studies thus far. It demonstrates certain imaging characteristics of SCC of the temporal bone in the setting of a chronic ear infection. The malignancy spreads to the posterior TMJ wall and the temporal lobe, which very few cases have shown. The tumor also invades specifically the mastoid and tympanic segments of the facial nerve canal. This may be one of the first cases to showcase these features given the rarity of their simultaneous occurrence.