Calcifying Pseudoneoplasm of the Neuraxis of the Foramen Magnum

A 31-year-old woman presented with headaches, dizziness, tinnitus, and syncope.She also experienced difficulty swallowing and impaired balance and coordination.Imaging revealed a 4 mm mass lesion at the right aspect of the foramen magnum on computed tomography, and subsequent magnetic resonance imaging confirmed that extra-axial lesion (Figure 1).Surgical resection was performed, and histology confirmed the presence of a calcifying pseudoneoplasm of the neuraxis (CAPNON) (Figure 2).Following surgery, the patient's condition improved, and she was discharged with recommendations for outpatient follow-up.CAPNON is a benign, rare entity characterized by slow-growing nonneoplastic fibro-osseous lesions and is distinguished by the presence of calcium deposits within the tumor tissue. 1,2The calcified material