Benign Tumors of the Anterior Cranial Base.

Abstract

Benign tumors of the anterior cranial base may originate from intracranial, cranial, or extracranial sites. Intracranial tumors such as meningiomas may secondarily involve the cranial base and extend into the sinuses or nasal cavity. Bony tumors arising from the cranium include benign fibro-osseous lesions such as osteoma, fibrous dysplasia, and ossifying fibroma. The most common extracranial tumors that may extend to the skull base include angiofibroma and inverted papilloma. Symptoms are nonspecific and diagnosis is often delayed. In most cases, a diagnosis can be established based on the clinical presentation and radiographic features. Some small asymptomatic tumors may be observed for growth (meningioma, osteoma), whereas others should be treated due to continued destructive growth (angiofibromas) or potential for malignancy (inverted papilloma). Surgery remains the predominant treatment modality for benign tumors of the anterior cranial base. The major advance in recent decades has been the adoption of endoscopic techniques. Advances in endoscopic transnasal surgery have dramatically altered the surgical landscape, enabling the removal of tumors of the anterior cranial base with minimal morbidity. Due to decreased morbidity in comparison to transfacial or transcranial approaches, endoscopic transnasal surgery has lowered the threshold for surgery for benign tumors and can be applied to adult as well as pediatric populations. Anatomical limits include the anterior cranial base from the frontal sinus to the sella and optic canals and laterally to the mid-plane of the orbital roofs. Large dural defects can be reliably reconstructed using local (nasoseptal) and regional (extracranial pericranial) vascularized flaps.