Foramen magnum osteochondroma causing myelopathy in a patient with hereditary multiple exostoses

BACKGROUND: Osteochondromas are commonly occurring benign bone tumors which may be either a solitary lesion or occur due to association with hereditary multiple exostoses (HMEs). There have been several reported cases of spinal osteochondromas, but intracranial lesions are rare. CASE DESCRIPTION: A 51-year-old male with a history of multiple osteochondromas presented with myelopathy. He had an exostosis arising from the foramen magnum causing compression of the cervical spinal cord that was successfully removed. Genetic testing revealed that he had HMEs. CONCLUSION: Osteochondromas of the skull are extremely rare. However, parts of the foramen magnum ossify in cartilage and can give rise to an osteochondroma. Here, we present a patient with HMEs who developed cervical myelopathy due to an osteochondroma arising from the foramen magnum. Due to the cartilaginous ossification of the foramen magnum, clinicians should be aware that osteochondromas can occur in this location and potentially give rise to cervical myelopathy.