Benign Enhancing Foramen Magnum Lesions: Clinical Report of a Newly Recognized Entity

Area of Science:

• Neuroimaging
• Radiology
• Neurosurgery

Background:

• Foramen magnum lesions can present as intradural extramedullary masses.
• Differential diagnoses include meningioma, nerve sheath tumor, aneurysm, and meningeal disease.
• Accurate identification is crucial to avoid misdiagnosis and unnecessary interventions.

Purpose of the Study:

• To describe a novel imaging finding at the foramen magnum that mimics pathological lesions.
• To characterize the imaging features and location of this specific finding.
• To emphasize its benign nature and potential to reduce patient anxiety.

Main Methods:

• Retrospective analysis of 14 patients with the described imaging finding.
• Detailed review of magnetic resonance imaging (MRI) sequences, including 3D-FLAIR, 3D gradient-echo, and 2D-TSE T2WI.
• Correlation of imaging findings with anatomical location.

Main Results:

• A specific lesion was identified at the foramen magnum, simulating disease.
• The lesion demonstrated hyperintensity on 3D-FLAIR and enhancement on 3D gradient-echo sequences.
• The lesion was not visualized on 2D-TSE T2WI and was located near the intradural vertebral artery.
• Follow-up imaging confirmed the stability of the lesion in affected patients.

Conclusions:

• A distinct imaging finding at the foramen magnum can mimic serious pathology.
• Recognition of this benign lesion, characterized by specific MRI signal intensities and location, is important.
• Identifying this finding can prevent misdiagnosis, unnecessary patient anxiety, and further investigations.