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| Year : 2000 | Volume
: 48
| Issue : 1 | Page : 75-7 |
Intramedullary spinal epidermoid cyst.
Chandra PS, Manjari T, Devi BI, Chandramouli BA, Srikanth SG, Shankar SK
Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
Correspondence Address:
Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
Intramedullary epidermoid cysts of the spinal cord are rare tumours, especially those not associated with spinal dysraphism. Around 50 cases have been reported in the literature. Of these, only seven cases have had magnetic resonance imaging studies. We report two cases of spinal intramedullary epidermoid cysts with MR imaging. Both were not associated with spina bifida. In one patient the tumour was located at D4 vertebral level, while in other within the conus medullaris. The clinical features, MR imaging characteristics and surgical treatment of such rare intramedullary benign tumours are discussed, and the relevant literature reviewed.
How to cite this article:
Chandra P S, Manjari T, Devi B I, Chandramouli B A, Srikanth S G, Shankar S K. Intramedullary spinal epidermoid cyst. Neurol India 2000;48:75 |
Intraspinal epidermoid cysts represent less than one percent of all intraspinal tumours in adults.[1] Intramedullary epidermoid tumours are still rarer. MR imaging has been reported in only seven cases previously.[1],[2],[3],[4],[5],[6],[7] We present two cases of intramedullary epidermoid tumours (IME) with magnetic resonance imaging (MRI) studies and review the relevant literature.
Case No. 1: An 18 year old girl presented with history of deep-seated pain in the left thigh for four years. She developed progressive difficulty in walking, associated with stiffness and paraesthesias for the last two years. There was no history of trauma or any procedure on the spine. Clinical examination revealed spastic paraparesis with power of grade 4 (MRC grading) on the left side and 3-4/5 on the right side. Sensory examination revealed a suspended sensory loss to pain from D6 to D9 segments and loss of all modalities of sensation below D12 segment. Sacral dermatomal sensations were preserved. Deep tendon reflexes were exaggerated in both the lower limbs. MRI showed evidence of an intramedullary tumour in the form of widening of the cord at D4-D5 levels, the lesion being hypointense on T1 weighted sequence and hyperintense on T2 sequence. The margins of the lesion had an irregular or a 'shaggy appearance' [Figure 1A] and [Figure 1B]. The patient underwent D3 to D6 laminectomy. At surgery, the cord was wide. Following a midline dorsal myelotomy, a pearly white and flaky lesion within the cord substance was seen. Near total excision of the lesion was performed using microneurosurgical techniques. Small portions of the capsule densely adherent to the cord parenchyma were left behind. The patient gradually improved and at six months of follow-up, she had power of grade 4+/5 with mild spasticity and was able to walk without support.
Case No. 2: A 28 year old female presented with history of pain in the right thigh and frequent incontinence of urine for the past six years. She had difficulty of gripping the footwear since three months. Clinical examination revealed weakness at the ankle joints with power of grade 3-4/5. Sensory examination revealed hypoaesthesia from L4-S2 dermatomes for all modalities of sensation. Ankle jerks were absent bilaterally. MRI revealed an intramedullary lesions within the conus-epiconus region expanding the cord. The lesion was hypointense on T1 sequence and hyperintense on T2 sequence. The margins of the lesion was well defined but had a 'shaggy border' [Figure - 2]. D12-L2 laminectomy was performed. The conusepiconus region was seen to be markedly expanded. A midline myelotomy was done and near total excision of the tumour including the capsule was performed. She improved and at four months of follow-up, there was minimal ankle weakness with power of grade 4/5, minimal patchy sensory hypoaesthesia and no urinary incontinence.
Histopathology: The wall of the lesion had a thin fibrous capsule, encircled by gliotic tissue. The luminal aspect was lined by compressed stratified squamous epithelium. The lumen contained degenerated squamous tissue. In case-1, dense chronic inflammatory infiltrate was noted within the wall, extending to the gliosed cord parenchyma. The features were characteristic of intramedullary epidermoid, with secondary inflammatory tissue.
The incidence of epidermoid cysts among intracranial tumours in most large series is estimated to be 0.2%-1%. It is much less amongst the spinal tumours. Guidetti and Gagliardi reported a series of 3844 intracranial and 452 intraspinal tumours in patients of all ages and found incidence of 0.8% for cranial epidermoid cysts and 0.7% for spinal epidermoid cysts. The incidence of intramedullary epidermoid cysts is still rarer.[8] The epidermoid cysts can be either congenital or acquired. Manno et al reported a series of 90 intraspinal epidermoid cysts collected from the literature, of which 39 were acquired and 51 congenital.[9] Acquired epidermoid cysts have been found years after single or multiple lumbar spinal punctures and are thought to result from iatrogenic penetration of skin fragments.[9],[10],[11] It is generally believed that congenital epidermoid cysts originate from displaced ectoderm inclusions arising in early foetal life and possibly may be associated with defective closure of the dural tube.[5],[9]
The frequency of intramedullary epidermoid tumours is low. Chiari reported the first case in 1833.[1],[5] Roux et al in 1989 reviewed and collected 46 patients from the literature and added one of their own case.[5] Since then four other cases have been reported.[3],[4],[6],[7]
Thoracic region is the favorite site of the intramedullary epidermoid cysts (especially between D4-D8 levels). The lumbar cord is the next common area. There are no reports of occurrence of intramedullary epidermoid cysts within the cervical canal. The association of these tumours with defect of the overlying bone is possible, but is less frequent than in dermoid or some extra medullary epidermoids.
Epidermoid cysts are generally characterized on MR images by an important variability of signal intensity between the different cases and, at times between the different parts of the same cysts; other features include the absence of oedema in surrounding tissue, fairly well defined limits and peripheral enhancement on injection of gadolinium. The disparity in signal intensity most likely reflects variable lipid and protein composition in these lesions. In addition we have noticed that the margins of these lesions are 'shaggy', possibly because of chronic inflammatory response to the squamous tissue 'leak' through the capsule and variable gliosis along the margin, extending into the cord. This feature may be of help in differentiating these lesions from other intramedullary tumours. To our knowledge, there have been only seven cases of intramedullary epidermoids with MR imaging reported in the literature earlier.[1],[2],[3],[4],[5],[6],[7]
Most authors do not attempt total removal of capsule, when it is intimately attached to the spinal cord or located within its confines. Attempts to remove the cyst wall completely under these circumstances are unnecessary and carry a high risk of neurological deficit. The risk of recurrence exists. However, in most cases, even partial removal of the intramedullary epidermoid resulted in total remission of symptoms. If recurrence does occur, another surgery may relieve the symptoms again.
| 1. | Penisson IB, Gilles G, Gandon Y: Intramedullary epidermoid cyst evaluated by computed tomographic scan and magnetic resonance imaging: Case Report. Neurosurgery 1989; 25: 955-959.  |
| 2. | Cornu P, Manai R, Foncin JF et al: Kyste epidermoide intra medullaire. Apport de 1' imagerie par resonance magnetique. Rev Neurol 1989; 145: 248-250. |
| 3. | Gallina P, Roux FX, Lo Re F et al: A rare case of intramedullary epidermoid cyst diagnosed by MRI. Neurochirurgie 1992; 38(6): 372-375. |
| 4. | Phillips J, Chiu L: Magnetic resonance imaging of intraspinal epidermoid cyst: a case report. J Comput Assist Tomogr 1987; 11: 181-183. |
| 5. | Roux A, Claude M, Larbrisseau A et al: Intramedullary epidermoid cysts of the spinal cord: a case report. J Neurosurg 1992; 76: 528-533. |
| 6. | Scholz M, Marzheuser BS, Gottschalk J et al: Intramedullary epidermoid cyst: A case report. Neurosurg Rev 1994; 17(1): 89-93. |
| 7. | Zavanone M, Guerra P, Rampini PM et al: A cervico-dorsal intramedullary epidermoid cyst. Case report and review of the literature. J Neurosurg Sci 1991; 35: 11-15. |
| 8. | Guidetti B, Gagliardi FM: Epidermoid and dermoid cysts. Clinical evaluation and late surgical results. J Neurosurg 1977; 47: 12-18. |
| 9. | Manno NJ, Uihlein A, Kernohan JW: Intraspinal epidermoids. J Neurosurg 1962; 19: 754-765. |
| 10. | Halcrow SJ, Crawford PJ, Craft AW: Epidermoid spinal cord tumour after lumbar puncture. Arch Dis Child 1985; 60: 978-979. |
| 11. | Shaywitz BA: Epidermoid spinal cord tumours and previous lumbar punctures. J Pediatr 1972; 80: 638-640. |
| 12. | Takeuchi J, Ohta T, Kajikawa H: Congenital tumours of the spinal cord. In Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. Vol 32: Congenital Malformations of the Spine and Cord. Amsterdam: North-Holland, 1978; 355-392. |
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