Calcified Pseudoneoplasm Of The Neuraxis

A patient presented with severe suboccipital headaches. Noncontrast CT was obtained and a densely calcified mass was found at the right cerebellomedullary angle cistern (figure 1). This lesion was followed clinically and with serial imaging. Follow-up MRI of the brain performed 8 months later demonstrated slightly increased mass effect and edema on the adjacent medulla and gross total surgical resection was performed. Final pathologic diagnosis was calcifying pseudoneoplasm of the neuraxis (CAPNON) (figure 2).