When It Is Not a Meningioma

Introduction: Meningioma is one of the three most common intracranial tumors, and by far and away the most common tumor to involve the extra axial intracranial system. One of the more common skull base locations is involving the sphenoid bone, particularly the greater wing, although, lesser wing involvement also occurs. It is important for neurosurgeons; however, to recognize that there is a differential diagnosis and other lesions may occur in the same area, sometimes mimicking meningiomas. The distinction becomes critical as treatment is often different.

Materials and Methods: A retrospective study of patients seen over the past 37 years has demonstrated multiple examples of inflammatory, infectious, and neoplastic processes that have mimicked meningioma involvement.

Results: Multiple techniques have been used to differentiate meningiomas from nonmeningiomatous lesions involving the sphenoid bone. These include radiographic analysis, immune markers, and the use of fine needle aspiration biopsy.

Conclusion: Not all lesions affecting the sphenoid bone are meningiomas, although the majority are. Making that distinction before radical surgery is planned can be highly advantageous, particularly in identifying inflammatory or metastatic disease that might otherwise be mistaken. We will review some of the useful techniques for distinction