* Introduction and anatomy
* Radiologic approach and review of anterior skull base masses
Dermoid and epidermoid cysts
The anterior skull base is a location where intracranial and sinus pathology can co-exist
The anterior skull base consists of the floor of the anterior cranial fossa, the roof of the nose, the ethmoid sinuses, and the orbits
Bones forming the anterior skull base include the ethmoid bone (cribriform plate and ethmoid sinus roof), frontal bones (orbital plates), and the sphenoid bone (planum sphenoidale and lesser wing)
Important to distinguish the location of the mass based on imaging features and understand the spectrum of pathology...
Imaging findings OR Procedure details
Anterior skull base meningiomas are classified into 3 types:
Olfactory groove meningioma
Planum sphenoidale meningioma
Tuberculum sellae meningioma
Generally well-circumscribed, smooth, or lobulated lesions
Isodense to hyperdense
± Intratumoral calcifications
Dural thickening may be present (dural tail sign)
± Restricted diffusion (due to high cellularity)
T1 isointense to hypointense
T2 isointense to hyperintense
Cephalocele is a generic term for protrusion of intracranial contents through a calvarial or skull base defect
The anterior skull base can be involved by both intracranial and sinus pathology
CT can be helpful in determining the anatomic origin of the mass (intracranial vs. extracranial)
Further characterization with MRI helps to narrow the differential diagnosis
Knowledge of the imaging features of anterior skull base masses is crucial in order to avoid unnecessary surgery and help plan a surgical approach should these masses require resection or repair
Alexiou, G. A., A. Zigouris, D. Pahaturidis, A. Goussia, S. Tsiouris, A. D. Fotopoulos, P. Zagorianakou and S. Voulgaris (2007). "Olfactory colloid cyst." Clin Neurol Neurosurg 109(10): 902-904.
Dhirawani, R. B., R. Gupta, S. Pathak and G. Lalwani (2014). "Frontoethmoidal encephalocele: Case report and review on management." Ann Maxillofac Surg 4(2): 195-197.
Francies, O., L. Makalanda, D. Paraskevopolous and A. Adams (2018). "Imaging review of the anterior skull base." Acta radiologica open 7(5): 2058460118776487-2058460118776487.
Hedlund, G. (2006). "Congenital frontonasal masses: developmental anatomy, malformations, and MR...