Skull base osteomyelitis: a rare but life-threatening illness

A 72-year-old man with type 2 diabetes was admitted to a hospital in Japan with a 2-month history of repeated falls and 1-month history of persistent severe headache. He had an unsteady gait, dysarthria, and dysphagia due to bilateral hypoglossal nerve palsy. Contrast-enhanced CT showed an ill-defined, poorly enhanced mass in the posterior wall of the nasopharynx that surrounded the bilateral internal carotid arteries (figure), with clival bone destruction. On T1-weighted MRI, high signal intensity of the bone marrow fat of the clivus was not present. Contrast-enhanced T1-weighted image and diffusion-weighted image on MRI added no further clarification. Massive bone destruction on CT and loss of bone marrow on MRI led to a suspected diagnosis of nasopharyngeal carcinoma.