Neuro--
Neuroradiology (1992) 34:447-448
radiology 9 Springer-Verlag 1992
Cystic spinal neurilemmoma on magnetic resonance imaging W. C. Shen 1, S. K. Lee 1, C.Y. Chang 2, and W. L. H o 2
Departments of t Radiology and ~Pathology, Taichung Veterans General Hospital, Taichung, Taiwan Received: 11 March 1991
Summary. We report a complete cystic change of intradural n e u r i l e m m o m a at the T12-L1 level. Tl-weighted M R I images with gadolinium-DTPA clearly enhanced the thin capsule of the cystic tumour.
cystic change is rarely found in extracranial nerve sheath tumours [2, 3]. We report complete cystic change in a thoracolumbar n e u r i l e m m o m a and illustrate the CT and M R I appearances.
Key words: N e u r o m a - S p i n e - N e o p l a s m s - Magnetic resonance imaging
Case report
Cystic intracranial neuromas are not rare; they show low density with marginal enhancement on CT [1]. Complete
A 41-year-old m a n had low back pain, radiating to both legs, for 2 years, For 3 months weakness of both legs and incontinence of urine and faeces overshadowed the pain.
Fig.1. a Sagittal Tl-weighted MRI (TRITE 500/20 ms). A low signal intensity lesion at T12-L1 distorts the conus medullaris and cauda equina. It is difficult to distinguish the lesion from CSF. b Sagittal image after intravenous gadolinium-DTPA. There is a thin rim of enhancement, c Field echo T2-weighted image (TRITE 400/10 ms, flip angle 10 ~ The lesion is of high intensity, equal to that of CSF, from which it is separated by only a thin septum inferiorly, d Axial gadolinium-enhanced image. Marginal enhancement outlines the low signal lesion
448 Examination showed sensory impairment below the T12 level, muscle atrophy, and loss of deep tendon reflexes in both lower legs. Myelography via lateral C1-2 puncture showed complete obstruction at T12-L1 by an intradural extramedullary lesion. CT showed a low density (21 Hounsfield units) tumour in the spinal canal. MRI (Fig. 1) revealed a smooth, thin-walled, cystic lesion, hypointense on T1 weighting with marginal enhancement after intravenous gadolinium-DTPA, and hyperintense on T2weighted images. Laminectomy disclosed a 7 x 1.5 x 1.5 cm cystic tumour connected to a nerve root of the cauda equina, which was totally removed after aspiration. Pathology showed a neurilemmoma with cystic change: Antoni type A and Antoni type B areas could be recognized in the wall of the cyst.
Discussion Kumar et al. [2] and Cohen et al. [3] report that low density of neuromas on CT may be due to hypocellular Antoni B tissue, cystic degeneration, or lipid rich Schwann cells, but complete cystic change is rare in extracranial nerve sheath tumours. Johansen and Stenwing [4] reported a completely cystic paraspinal schwannoma. In our case, CT showed a low density lesion in the spinal canal. However, owing to the benefit of sagittal sections, MRI depicted the lesion more clearly. Homogeneous hypointensity on T1 weighting and hyperintensity on T2 weighting hinted at its cystic nature, and Tl-weighted images with gadolinium-DTPA enhancement demonstrated more clearly its smooth, thin capsule.
Arachnoid cyst and an ependymoma arising from the conus medullaris or filum terminale must be included in the differential diagnosis. The former has the same intensity characteristics [5], but there is no marginal contrast enhancement of its capsule. Most ependymomas are solid, although mucinous degeneration is not uncommon; however, mucinous material, proteineous in nature, would also be expected to have increased signal on Tl-weighted images [6].
References 1. Wu EH, Tang YS, Zhang YT, Bai RJ (1986) CT in diagnosis of acoustic neuromas. AJNR 7:645-650 2. Kumar AJ, Kuhajda FR Martinez CR, Fishman EK, Jezic DV, Siegelman SS (1983) Computed tomography of extracranial nerve sheath tumours with pathological correlation. J Comput Assist Tomogr 7:857-865 3. Cohen LM, Schwartz AM, Rockoff SD (1986) Benign schwannomas: pathologic basis for CT inhomogeneities. A JR 147:141-143 4. Johansen JG, Stenwing JT (1987) Paraspinal schwannomas with cystic appearance on CT. Neuroradiology 29:314 5. Gray L, Djang WT, Friedman AH (1988) MR imaging of thoracic extradural arachnoid cysts. J Comput Assist Tomogr 12:646-648 6. Wagle WA, Janfman B, Mincy JE (1988) Intradural extramedullary ependymoma: MR-pathologic correlation. J Comput Assist Tomogr 12:705-707 Dr. Wu-chung Shen Department of Radiology Taichung Veterans General Hospital Taichung 407, Taiwan Republic of China
Neuroradiology (1992) 34:447-448
radiology 9 Springer-Verlag 1992
Cystic spinal neurilemmoma on magnetic resonance imaging W. C. Shen 1, S. K. Lee 1, C.Y. Chang 2, and W. L. H o 2
Departments of t Radiology and ~Pathology, Taichung Veterans General Hospital, Taichung, Taiwan Received: 11 March 1991
Summary. We report a complete cystic change of intradural n e u r i l e m m o m a at the T12-L1 level. Tl-weighted M R I images with gadolinium-DTPA clearly enhanced the thin capsule of the cystic tumour.
cystic change is rarely found in extracranial nerve sheath tumours [2, 3]. We report complete cystic change in a thoracolumbar n e u r i l e m m o m a and illustrate the CT and M R I appearances.
Key words: N e u r o m a - S p i n e - N e o p l a s m s - Magnetic resonance imaging
Case report
Cystic intracranial neuromas are not rare; they show low density with marginal enhancement on CT [1]. Complete
A 41-year-old m a n had low back pain, radiating to both legs, for 2 years, For 3 months weakness of both legs and incontinence of urine and faeces overshadowed the pain.
Fig.1. a Sagittal Tl-weighted MRI (TRITE 500/20 ms). A low signal intensity lesion at T12-L1 distorts the conus medullaris and cauda equina. It is difficult to distinguish the lesion from CSF. b Sagittal image after intravenous gadolinium-DTPA. There is a thin rim of enhancement, c Field echo T2-weighted image (TRITE 400/10 ms, flip angle 10 ~ The lesion is of high intensity, equal to that of CSF, from which it is separated by only a thin septum inferiorly, d Axial gadolinium-enhanced image. Marginal enhancement outlines the low signal lesion
448 Examination showed sensory impairment below the T12 level, muscle atrophy, and loss of deep tendon reflexes in both lower legs. Myelography via lateral C1-2 puncture showed complete obstruction at T12-L1 by an intradural extramedullary lesion. CT showed a low density (21 Hounsfield units) tumour in the spinal canal. MRI (Fig. 1) revealed a smooth, thin-walled, cystic lesion, hypointense on T1 weighting with marginal enhancement after intravenous gadolinium-DTPA, and hyperintense on T2weighted images. Laminectomy disclosed a 7 x 1.5 x 1.5 cm cystic tumour connected to a nerve root of the cauda equina, which was totally removed after aspiration. Pathology showed a neurilemmoma with cystic change: Antoni type A and Antoni type B areas could be recognized in the wall of the cyst.
Discussion Kumar et al. [2] and Cohen et al. [3] report that low density of neuromas on CT may be due to hypocellular Antoni B tissue, cystic degeneration, or lipid rich Schwann cells, but complete cystic change is rare in extracranial nerve sheath tumours. Johansen and Stenwing [4] reported a completely cystic paraspinal schwannoma. In our case, CT showed a low density lesion in the spinal canal. However, owing to the benefit of sagittal sections, MRI depicted the lesion more clearly. Homogeneous hypointensity on T1 weighting and hyperintensity on T2 weighting hinted at its cystic nature, and Tl-weighted images with gadolinium-DTPA enhancement demonstrated more clearly its smooth, thin capsule.
Arachnoid cyst and an ependymoma arising from the conus medullaris or filum terminale must be included in the differential diagnosis. The former has the same intensity characteristics [5], but there is no marginal contrast enhancement of its capsule. Most ependymomas are solid, although mucinous degeneration is not uncommon; however, mucinous material, proteineous in nature, would also be expected to have increased signal on Tl-weighted images [6].
References 1. Wu EH, Tang YS, Zhang YT, Bai RJ (1986) CT in diagnosis of acoustic neuromas. AJNR 7:645-650 2. Kumar AJ, Kuhajda FR Martinez CR, Fishman EK, Jezic DV, Siegelman SS (1983) Computed tomography of extracranial nerve sheath tumours with pathological correlation. J Comput Assist Tomogr 7:857-865 3. Cohen LM, Schwartz AM, Rockoff SD (1986) Benign schwannomas: pathologic basis for CT inhomogeneities. A JR 147:141-143 4. Johansen JG, Stenwing JT (1987) Paraspinal schwannomas with cystic appearance on CT. Neuroradiology 29:314 5. Gray L, Djang WT, Friedman AH (1988) MR imaging of thoracic extradural arachnoid cysts. J Comput Assist Tomogr 12:646-648 6. Wagle WA, Janfman B, Mincy JE (1988) Intradural extramedullary ependymoma: MR-pathologic correlation. J Comput Assist Tomogr 12:705-707 Dr. Wu-chung Shen Department of Radiology Taichung Veterans General Hospital Taichung 407, Taiwan Republic of China
