Extensive Skull Base Osteomyelitis Secondary to Malignant Otitis Externa

Skull base osteomyelitis is a severe complication of malignant otitis externa that affects the marrow of the temporal, sphenoid, and occipital bones. Skull base osteomyelitis is usually diagnosed based on clinical, microbiological, and radiological findings. Here, we present the imaging findings of a 76-year-old man who initially presented with right-sided malignant otitis externa, with the involvement of the otomastoid structures and ipsilateral temporal bone. Over the following 3 years, despite specific extended antibiotic therapy, the skull base osteomyelitis entirely involved the skull base, up to the contralateral petrous portion of the temporal bone, and it affected the cervical vertebral processes. This report describes an exceptional extent of unilateral malignant otitis externa with a severe involvement of the skull base on the contralateral side and the cervical spine.