Metastasis from an unknown primary presenting as a tumor in the internal auditory meatus

A 40-year-old male presented with a 2-month history of sudden hearing loss and tinnitus in his left ear. Mild vertigo was present initially but disappeared spontaneously without treatment. Facial nerve paralysis and retroauricular pain appeared 3 months after the onset of hearing loss on the same side. Computerized tomography and magnetic resonance imaging demonstrated a 1-cm mass in the left internal auditory canal. Translabyrinthine removal of tumor revealed metastatic adenocarcinoma. The patient died 3 months postoperatively from multiple metastatic deposits. A primary tumor was never found. The course of illness in this patient differs significantly from the typical course of other conditions involving the internal auditory canal. A metastatic work-up should be considered for patients with a similar history before a craniotomy is performed.