DOI: 10.1148/radiol.2412040203
(Radiology 2006;241:614-617.)
© RSNA, 2006
Case 100: Spinal Epidural Meningioma1
Sahar M. El Khamary, MD and
Ibrahim A. Alorainy, MD
1 From the College of Medicine and King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia. Received January 29, 2004; revision requested March 31; revision received May 4; accepted May 24; final version accepted June 25.
Correspondence: Address correspondence to S.M.E.K., Department of Radiology and Medical Imaging, Mansoura University Hospital, PO Box 310, Mansoura 35511, Egypt (e-mail: selkhamary{at}hotmail.com).
 |
HISTORY
|
|---|
A previously healthy 13-year-old girl presented with gradual onset of weakness in both legs and bowel and bladder incontinence. Her symptoms worsened over a 2-month period. A neurologic examination revealed muscle tone and tendon reflexes were increased in the legs. There was no muscle wasting, and power was graded as 4 out of 5 in all muscle groups (ie, active movement against activity, with some resistance). Sensation was impaired from T7 through T11 vertebrae. There was no back pain or deformity or tenderness over the spine. There was no fever or sign of an upper respiratory tract infection and no history of trauma, night sweats, or hematologic disease. Magnetic resonance (MR) imaging of the dorsal spine was performed.
|
IMAGING FINDINGS
|
|---|
The sagittal T1-weighted (Fig 1a) and T2-weighted (Fig 1b) MR images showed a well-circumscribed smoothly marginated spindle-shaped solid mass within the posterior epidural space of the middorsal region extending from the T7 vertebral level to the upper border of the T10 vertebra and surrounded by normal epidural fat at its upper and lower ends. Signal intensity of the mass was similar to that of the spinal cord on T1-weighted images and mixed on T2-weighted images. Furthermore, the mass deformed the thecal sac, obliterated the posterior subarachnoid space, and compressed the dorsal spinal cord. Gadopentetate dimeglumine–enhanced (Magnevist; Schering, Berlin, Germany) MR images obtained in the sagittal (Fig 2a) and transverse (Fig 2b) planes revealed intense and homogeneous enhancement of the mass. Linear enhancement at the caudal margin of the tumor was probably an extension of the tumor or the enhancing vascular channel rather than the dural tail. There was no evidence of osseous infiltration or destruction. The bone marrow of the spine showed a normal signal intensity pattern with no abnormal enhancement. No extension through the intervertebral foramina or intradural involvement was identified.
View larger version (89K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1a: Fast spin-echo sagittal images of the dorsal spine. (a) T1-weighted (repetition time msec/echo time msec, 500/20; section thickness, 4 mm) image shows the posterior epidural mass (arrow) has signal intensity similar to that of the spinal cord. The subarachnoid space is obliterated at the level of the mass, and the spinal cord is compressed. Note the normal shape and signal intensity of the vertebrae. (b) T2-weighted (4000/111; section thickness, 4 mm) image shows the mass has mixed signal intensity, with dura mater seen as a dark line (arrow) separating the extradural mass from the intradural structures. High signal intensity within the compressed spinal cord probably represents edema secondary to compression.
|
|
View larger version (95K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1b: Fast spin-echo sagittal images of the dorsal spine. (a) T1-weighted (repetition time msec/echo time msec, 500/20; section thickness, 4 mm) image shows the posterior epidural mass (arrow) has signal intensity similar to that of the spinal cord. The subarachnoid space is obliterated at the level of the mass, and the spinal cord is compressed. Note the normal shape and signal intensity of the vertebrae. (b) T2-weighted (4000/111; section thickness, 4 mm) image shows the mass has mixed signal intensity, with dura mater seen as a dark line (arrow) separating the extradural mass from the intradural structures. High signal intensity within the compressed spinal cord probably represents edema secondary to compression.
|
|
View larger version (94K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2a: Contrast material–enhanced (a) sagittal and (b) transverse T1-weighted fast spin-echo MR images of the dorsal spine obtained with frequency-selective fat saturation (467/15; section thickness, 4 mm) depict strong and homogeneous contrast enhancement of the posterior epidural mass (arrow). In b, note complete filling of the posterior epidural space and lack of extension through the intervertebral foramina to the paravertebral space.
|
|
View larger version (73K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2b: Contrast material–enhanced (a) sagittal and (b) transverse T1-weighted fast spin-echo MR images of the dorsal spine obtained with frequency-selective fat saturation (467/15; section thickness, 4 mm) depict strong and homogeneous contrast enhancement of the posterior epidural mass (arrow). In b, note complete filling of the posterior epidural space and lack of extension through the intervertebral foramina to the paravertebral space.
|
|
|
DISCUSSION
|
|---|
There are many causes of epidural mass lesions in the pediatric population, and determination of the cause of lesions on the basis of imaging findings and clinical presentation is crucial when deciding to treat a lesion conservatively or with surgery. MR imaging enables recognition of these lesions and helps us to assign the correct preoperative diagnosis.
Meningiomas are believed to account for about 25% of all spinal tumors. The majority of meningiomas are intradural tumors that arise at the thoracic level. Meningiomas also occur in the cervical and lumbar regions, albeit less frequently. They occur most commonly in middle-aged women (1,2) and extremely rarely in children (3). It is uncommon for a spinal meningioma to have an epidural location; in fact, epidural meningiomas account for only 3.5%–7.0% of all spinal meningiomas (4,5) and occur more commonly in children than in adults (6).
There are several hypotheses that concern the epidural origin of meningiomas: One is that meningiomas originate from the segment of the nerve root where the arachnoid mater is in contact with the dura mater (2,7). Another suggests that the tumor originates from aberrant arachnoid islets in the epidural space. This hypothesis is supported by the findings in several case reports, such as intraorbital meningioma with no relation to the sheath of the optic nerve or extracranial meningioma between the galea and the bone (7,8). The third hypothesis is that epidural meningioma originates directly from the external surface of the dura mater (cap cells) and then grows into the extradural space with a globular or en plaque pattern (1,4). This hypothesis is supported by the fact that the outer dural layer is periosteum and not true dura mater; therefore, it does not contain arachnoidal rests (ie, embryonic meningothelial cells in the arachnoid layer that have an ectopic location in any area outside the dura) (3).
On T1-weighted images, spinal meningioma tends to have a signal intensity similar to that of the spinal cord and does not exhibit substantial increased signal intensity on T2-weighted images. In addition, contrast enhancement is immediate and homogeneous (1). Lack of foraminal extension favors a diagnosis of meningioma over a diagnosis of schwannoma or neurofibroma. The latter two lesions usually demonstrate higher signal intensity on T2-weighted images, cystic changes, and inhomogeneous enhancement. Hyperostosis is seen less frequently in patients with epidural spinal meningiomas than in patients with cranial counterparts of these lesions. This is attributed to the wide epidural space between the dura mater and bone that is filled with fat, venous channels, and spinal nerve roots (3).
Most malignant epidural masses in children are histologically characterized by small round cells and include lymphoma, neuroblastoma, leukemia, undifferentiated primitive neuroectodermal tumors, extraosseous Ewing sarcoma, and rhabdomyosarcoma. The majority of these lesions traverse several compartments and are associated with bone marrow and paravertebral involvement (9). Lymphoma tends to extend over many vertebral levels, with an encircling rind of anterior epidural tumor effacing the subarachnoid space in addition to bone marrow infiltration and paravertebral extension (10). Lymphomas usually have homogeneously low signal intensity on T2-weighted images because of their dense cellularity (11). Neuroblastomas are seen in young children and involve the epidural space by means of extension from a paraspinal origin. On MR images, the tumor usually shows calcifications and heterogeneous texture with inhomogeneous enhancement (12). In long-standing lesions, the intraspinal mass causes expansion of the spinal canal and neural foramina with vertebral scalloping. In patients with leukemia, the vertebral bone marrow signal is expected to be altered. Undifferentiated primitive neuroectodermal tumors, extraosseous Ewing sarcoma, and rhabdomyosarcoma enhance heterogeneously. There is usually a paravertebral component to rhabdomyosarcoma.
Extramedullary hematopoiesis (EMH) was unlikely in this patient because EMH usually appears as an extensive long epidural mass associated with diffusely abnormal signal intensity of the vertebral marrow (13). A diagnosis of EMH should be considered only if the patient is known to have chronic anemia. Lack of high T1 signal intensity in this patient led us to exclude a diagnosis of epidural lipoma. Homogeneous enhancement of the lesion led us to exclude a diagnosis of abscess or hematoma. This patient underwent surgery, and the diagnosis of epidural meningioma was confirmed.
In summary, one should make the most likely diagnosis of spinal posterior epidural meningioma in this patient on the basis of the intermediate signal intensity seen on the T2-weighted image, the pattern of homogeneous enhancement, and the patient's lack of blood disease and fever. Lack of foraminal extension and a paravertebral component make diagnosis of meningioma more likely than diagnosis of the other neurogenic tumors, such as schwannoma or neuroblastoma.
|
FOOTNOTES
|
|---|
| Part one of this case appeared 4 months previously and may contain larger images.
|
|
References
|
|---|
- Gambardella G, Toscano S, Staropoli C, et al. Epidural spinal meningioma: role of magnetic resonance in differential diagnosis. Acta Neurochir (Wien) 1990;107:70–73.[CrossRef][Medline]
- Kumar S, Kaza R, Maitra TK, Chandra M. Extradural spinal meningioma arising from a nerve root: case report. J Neurosurg 1980;52:728–729.[Medline]
- Kaya U, Özden B, Turantan MI, Aydin Y, Barlas O. Spinal epidural meningioma in childhood: a case report. Neurosurgery 1982;10:746–747.[Medline]
- Haft H, Shenkin HA. Spinal epidural meningioma: case report. J Neurosurg 1963;20:801–804.[Medline]
- Weil SM, Gewirtz RJ, Tew JM. Concurrent intradural and extradural meningioma of the cervical spine. Neurosurgery 1990;27:629–631.[Medline]
- Messori A, Rychlicki F, Salvolini U. Spinal epidural en-plaque meningioma with an unusual pattern of calcification in a 14-year-old girl: case report and review of the literature. Neuroradiology 2002;44:256–260.[CrossRef][Medline]
- Sato N, Sze G. Extradural spinal meningioma: MRI. Neuroradiology 1997;39:450–452.[CrossRef][Medline]
- Alorainy IA. Sequestrated meningocele of the scalp. Eur J Radiol 2001;40:151–153.[CrossRef][Medline]
- Packer RJ, Zimmerman RA, Sutton LN, Bilaniuk LT, Bruce DA, Schut L. Magnetic resonance imaging of spinal cord disease of childhood. Pediatrics 1986;78:251–256.[Abstract/Free Full Text]
- Boukobza M, Mazel C, Touboul E. Primary vertebral and spinal epidural non-Hodgkin's lymphoma with spinal cord compression. Neuroradiology 1996;38:333–337.[Medline]
- Lyons MK, O'Neill BP, March WR, Kurtin DJ. Primary spinal epidural non-Hodgkin's lymphoma: report of eight patients and review of literature. Neurosurgery 1992;30:675–680.[Medline]
- Dietrich RB, Kangarloo H, Lenarsky C, Feig SA. Neuroblastoma: the role of MR imaging. AJR Am J Roentgenol 1987;148:937–942.[Abstract/Free Full Text]
- Alorainy IA, Al-Asmi AR, del Carpio R. MRI features of epidural extramedullary hematopoiesis: case report. Eur J Radiol 2000;35:8–11.[CrossRef][Medline]
Congratulations to the 41 individuals and one resident group that submitted the most likely diagnosis (spinal epidural meningioma) for Diagnosis Please, Case 100. The names and locations of the individuals and resident groups, as submitted, are as follows:
Individual responses
- James H. Algeo, Jr, MD, El Paso, Tex
- Lionel Arrivé, Paris, France
- Aaron Scott Bailey, MD, San Antonio, Tex
- Ronald N. Boyle, MD, La Plata, Md
- Peter C. Buetow, MD, Bellingham, Wash
- Dr Marcelo F. Cabrini, Buenos Aires, Argentina
- Aldo Camenzuli, Liverpool, United Kingdom
- Martin Campi, Godoy Cruz, Mendoza, Argentina
- Theresa M. Corrigan, Louisville, Ky
- Alberto Cuñat, Valencia, Spain
- Thuan T. Dang, MD, Colton, Calif
- J. F. K. de Villiers, Gisborne, New Zealand
- Jon James De Witte, Bishop, Ga
- Seyed Emamian, MD, PhD, Rockville, Md
- Alfredo Miguel Fernandez de Castro Assis, Spain
- Francis Flaherty, MD, Ridgefield, Conn
- Ram Prakash Galwa, Chandigarh, India
- Karthik Ganesan, Mumbai, India
- Pedro Garcia, MD, Gijon, Spain
- William Gawman, MD, Waterloo, Ontario, Canada
- D. M. Ghookal, MBBCh, Regina, Saskatchewan, Canada
- Mark G. Goldshein, MD, Andover, Mass
- Umapathi Mahesh, Sr, MBBS, DMRD, Kerala, India
- Naganathan B. S. Mani, MD, Nassau, Bahamas
- Koen Pieter Mermuys, MD, Heverlee, Belgium
- Nikolaos Michailidis, MD, Thessaloniki, Greece
- Mahesh Kumar Neelala Anand, FRCR, Greater Manchester, United Kingdom
- Ann Burleson Owen, MD, Murfreesboro, Tenn
- Yeliz Pekcevik, Izmir, Turkey
- Hatice Tuba Sanal, MD, Ankara, Turkey
- Marius Stellmann, MD, Stade, Germany
- Venkateswar Rao Surabhi, MBBS, Herndon, Va
- William C. Torreggiani, MB, Dublin, Ireland
- Dr Özgür Tosun, Bilkent, Ankara, Turkey
- Unni K. Udayasankar, MD, FRCR, Atlanta, Ga
- Eleni Vafeiadou, Thessaloniki, Greece
- Jesús Ig. Vivancos, MD, Tenerife, Spain
- Sanjay Ramaswamy Vydianath, MRCP, FRCR, Wolverhampton, United Kingdom
- Ensar Yekeler, MD, Istanbul, Turkey
- Stanko Yovichevich, MD, Sydney, Australia
- Joe Yut, Olathe, Kan
Resident group response
- University of Pennsylvania Radiology Residents, Philadelphia, Pa
This article has been cited by other articles:
|
|
|
|
 
M. K. Demir, H. Ozdemir, E. Unlu, O. Temizoz, H. Genchellac, and S. M. El Khamary
Differential Diagnosis of Spinal Epidural Meningioma and Hemangioma at MR Imaging
Radiology,
September 1, 2007;
244(3):
933 - 934.
[Full Text]
[PDF]
|
|
|
TOP
HISTORY
IMAGING FINDINGS
