FROM THE RADIOLOGIC PATHOLOGY ARCHIVES | NEUROLOGIC/HEAD AND NECK IMAGING 468 Intradural Extramedullary Spinal Neoplasms: Radiologic-Pathologic Correlation While intradural extramedullary spinal disease varies widely, iden- tification of tumors in this location and their radiologic manifesta- tions greatly facilitates narrowing of the diagnostic considerations. Meningioma and schwannoma are the two most common intradu- ral extramedullary tumors, and both are associated with neurofibro- matosis. Meningiomas are most common in the thoracic spine and show a strong female predilection and a clinical manifestation relat- ed to compression of the spinal cord or nerve roots. Schwannomas typically are associated with radicular pain and other sensory symp- toms. Melanotic schwannoma frequently shows T1 hyperintensity at MRI related to the presence of paramagnetic free radicals in melanin. Neurofibroma, known for its T2 hyperintensity, frequently involves the cervical spine, where it may make surgical resection challenging. Less commonly, malignant peripheral nerve sheath tu- mor commonly mimics the imaging appearance of a schwannoma but has decidedly more aggressive biologic behavior. In the cauda equina, myxopapillary ependymoma and paraganglioma are be- lieved to arise from the filum terminale and have characteristic im- aging manifestations based on their underlying pathologic features. Recent identification of a common genetic marker has led to reclas- sification of what had previously been regarded as separate tumors and are now known as solitary fibrous tumor/hemangiopericytoma. In the proper clinical setting, the presence of nodular intradural enhancement strongly suggests the presence of leptomeningeal metastatic disease, even when results of cerebrospinal fluid analysis are negative. This article highlights the characteristic neuroimaging manifestations of these neoplasms, with emphasis on radiologic- pathologic correlation. Kelly K. Koeller, MD RobertY. Shih, LTC, MC, USA Abbreviations: CNS = central nervous system, CSF = cerebrospinal fluid, H-E = hematoxylin- eosin, HPC = hemangiopericytoma, MPNST = malignant peripheral nerve sheath tumor, NF1 = neurofibromatosis type 1, NF2 = neurofibro- matosis type 2, SFT = solitary fibrous tumor, WHO = World Health Organization RadioGraphics 2019; 39:468–490 https://doi.org/10.1148/rg.2019180200 Content Codes: From the Department of Neuroradiology, American Institute for Radiologic Pathology, 1011 Wayne Ave, Suite 320, Silver Spring, MD 20910 (K.K.K., R.Y.S.); Department of Radiol- ogy, Mayo Clinic, Rochester, Minn (K.K.K.); Uniformed Services University of the Health Sciences, Bethesda, Md (R.Y.S.); and Depart- ment of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (R.Y.S.). Received August 26, 2018; revision requested October 5 and received October 31; accepted November 2. For this journal-based SA-CME activity, the author K.K.K. has provided disclosures (see end of article); the other author, the editor, and the reviewers have disclosed no relevant relationships. Address correspondence to K.K.K. (e-mail: [email protected]). Supported by the American Institute for Radio- logic Pathology, the Joint Pathology Center, and Uniformed Services University of the Health Sciences. The views expressed in this article are those of the authors and do not necessarily re- flect the official policy or position of the Depart- ment of Defense or the U.S. Government. After completing this journal-based SA-CME activity, participants will be able to: ■ List common and noteworthy less com- mon intradural extramedullary spinal neoplasms. ■ Describe the radiologic manifestations of these neoplasms. ■ Discuss correlation of the imaging findings with the underlying pathologic features. See rsna.org/learning-center-rg. SA-CME LEARNING OBJECTIVES Introduction Spinal tumors are comparatively rare, comprising approximately 5%– 10% of all central nervous system (CNS) tumors, with an estimated 70%–80% being intradural extramedullary in location (1). While their appearances are not always pathognomonic, assessment with MRI frequently allows identification of important characteristic features that tailor the diagnostic considerations in many cases to a single most likely diagnosis. As many of these tumors are affiliated with the spinal nerves or dura mater, schwannomas and meningiomas are the most common to occur in this location. Which of these tumors is the single most common intradural extramedullary neoplasm is controversial. While many sources have traditionally cited schwannoma (typically reported as 30%–50% of cases) as the most common primary intra- dural extramedullary spinal tumor and meningioma (at 20%–25%) as the second most common, a review of 5564 primary intradural spinal tumors in the Surveillance, Epidemiology, and End Results (SEER) This copy is for personal use only. To order printed copies, contact [email protected]
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
