Hyperpneumatization of the skull base: case report

Temporal bone and skull base pneumatization is a naturally occurring process that begins before birth and continues into early adulthood. Occasionally this process surpasses normal limits, resulting in hyperpneumatization, which is usually obvious, but on rare occasions may mimic more aggressive skull base disorders. An awareness of this rare anatomical variant may help clinicians avoid more extensive investigations.

We present the case of a 37-year-old man with severe headache and multiple, partially opacified lytic lesions in the skull base noted after minor head trauma. At presentation, a computed tomographic (CT) head scan revealed multiple lucent areas in the skull base after which magnetic resonance imaging (MRI) further suggested the diagnosis of an extensive lytic skull base process associated with a small clival fracture. Needle biopsy revealed nonspecific inflammation. An earlier head CT, not available at the time of admission, demonstrated extensive pneumatized air cells in the basiocciput. During the course of the 2-year follow-up, the originally pneumatized skull base was noted to become permanently opacified with areas of new bone growth.

We concluded that the skull base abnormality was an anatomical variant associated with a clival fracture and hemorrhage, which led to opacification of the pneumatized air cells. No specific treatment was offered and symptoms resolved completely. Long-term follow-up CT demonstrated opacification of the skull base. This is one of very few cases in the literature reporting the clinical course of a patient with a hyperpneumatized skull base and the subsequent evolution of the disorder after minor head trauma.