These findings on imaging are likely indicative of a benign enhancing foramen magnum lesion.

The differential diagnosis includes schwannoma and meningioma.

Recently, a pathology report was issued regarding benign enhancing foramen magnum lesions. After surgery, the authors found that these lesions were fibrotic arachnoid nodules adherent to the dorsal aspect of the spinal accessory nerve. These pathology-proven lesions are benign and do not require surgical resection ¹.