Non-dysraphic intramedullary spinal cord lipoma. A case report

CASE REPORT

Non-dysraphic intramedullary spinal cord lipoma.

A case report

Brahim El Mostarchid, Akhdar Ali, M. Maftah, A. Mansouri, J. Laghzioui, B. Kadiri, M. Gazzaz, M. Chafiq, Mohammed Boucetta*

Neurosurgery department of Mohamed V Military Hospital, Ryad, Rabat, Morocco

(Submitted for publication September 25, 2001; accepted in revised form December 12, 2001)

Summary – Non-dysraphic spinal cord lipomas are rare benign lesions, accounting for approximately 1%

of all spinal cord tumors. Patients usually present with long histories of disability followed by rapid progression of their symptoms. Presenting symptoms include spinal pain, dysesthesic sensory changes, gait difficulties, weakness, and incontinence. Magnetic resonance imaging is the examination of choice. The T1- and T2-weighted images show increased and decreased signal intensity, respectively. The goal of intervention is decompression and generous debulking following by duraplasty. Early diagnosis of spinal cord lipomas and early surgery is advanced prior to irreversible disease progression. One new case of true non-dysraphic cervicodorsal spinal cord lipoma is reported. Joint Bone Spine 2002 ; 69 : 511-4. © 2002 Éditions scientifiques et médicales Elsevier SAS

intramedullary spinal cord lipoma / MR imaging / partial removal

INTRODUCTION

Non-dysraphic spinal cord lipomas are rare lesions, accounting for approximately 1% of all spinal cord tumors. True intramedullary spinal cord lipomas are extremely rare and are represented in the literature as scattered, single case reports [1-8].

The emergence of modern imaging techniques and improved microsurgical capabilities has resulted in a few case reports of intramedullary lipomas in the more recent literature. Only 100 cases have been reported in the literature since 1995. We present a case of non- dysraphic intramedullary spinal cord lipoma managed at our institution.

CASE REPORT

A 26-year-old Moroccan men presented at 19 and 21 years of age with upper thoracic pain and bilateral dysesthetic leg pain which resolved spontaneously over 2 months. Five months prior to his hospitalization, he developed a rapid paraparesis with associated gait diffi- culties. At examination, there was spastic weakness of the legs and hyperreflexia, clonus of the left ankle, extensor plantar responses, decreased sensation of pain and temperature below T4 level, and decreased sensa- tion of vibration in the feet. Magnetic resonance imag- ing disclosed an intraspinal intramedullary lipoma. The T1- and T2-weighted images showed increased and decreased signal intensity respectively, extending from the C-6 to the T-4 level. (figures 1 and 2). There was no enhancement with gadolinium.

*Correspondence and reprints.

Joint Bone Spine 2002 ; 69 : 511-4

© 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved

S1297319X02004402/SCO

He underwent C6-T4 laminectomy. After opening the dura, a microscope was used to continue the proce- dure. The lipoma was posterior, under pia and intramedullary, and the cord was pushed laterally. The radicelles emerged laterally from the lipoma. A good debulking of the lipoma was carried out. At no time was an attempt made to approach the interface between lipoma and spinal cord tissue because of the risk of neurological injury. The surgical goal was to debulk the lipoma to achieve internal decompression of the spinal cord. After debulking, the dura was easily closed with- out a patch graft. Histologically, the tumor was uni- formly composed of mature adipose tissue.

Postoperatively, the patient was able to walk. He left hospital 10 days later. At 10 months follow-up, his examination show a moderate hyperreflexia. No motor

Figure 1. Magnetic resonance images (MR). A T1-weighted non- contrast-enhanced image, sagittal view showing increased signal intensity of intramedullary lipoma extending from C6 to T4. Cervico- thoracic intramedullary lipoma.

Figure 2. Magnetic resonance images (MR). A T1-weighted coronal view on T1 showing increased signal intensity of an intramedullary

lipoma. Figure 3. Postoperative MR images, sagittal view, showing approxi-

mately 60% resection.

512 B. El Mostarchid et al.

deficit was noted. Postoperative MR imaging showed that 60% of the lipoma had been resected (figure 3).

DISCUSSION

Spinal cord lipoma without spinal dysraphism is a rare tumor, with just over 100 cases reported since 1995 [5].

Most reported cases are adults [2-4, 8]; it is very rare in children [6, 7]. Cervical intraspinal cord lipoma in a 14-month-old girl and cervical intramedullary lipomas with intracranial extension in an infant have been reported [6]. Cervical intramedullary lipomas with intracranial extension in an infant have also been reported. The thoracic area is the most frequently reported localization. A holocord intradural lipoma extending from the cervical to the lumbar spine is an exceedingly rare condition [8].

The clinical presentation of intramedullary spinal cord lipoma is the same as for other intramedullary spinal cord tumors. The lesion may mimic any cause of spinal cord compression including malignancy, and distinguishing it from these other diseases is very impor- tant for the prognosis and management. At presenta- tion, all patients presented with neck or back pain, gait difficulties, weakness and dysesthetic symptoms. These symptoms varied in location depending on the tumor site. Patients usually presented with long histories of disability followed by a rapid progression of their symp- toms. Most patients were in poor neurological condi- tion on presentation. Presenting symptoms included spinal pain, dysesthetic sensory changes, gait difficul- ties, weakness, and incontinence [2, 3, 5]. Our patient presented two episodes of upper thoracic pain and leg weakness spontaneously resolved, respectively 6 and 3 years before the diagnosis. No weight gain was noted during these two episodes.

The MR imaging is the examination of choice [2-4, 8]. The T1- and T2-weighted images showed increased and decreased signal intensity, respectively. There was no enhancement with gadolinium. Computerized tomography scans showed the lesions to be of low density. Plain radiographs can show changes suggestive of an indolent mass lesion with enlargement of the spinal canal and scalloping of the vertebrae.

Most surgeons reporting on intradural lipomas have commented on the difficulty of removing these tumors.

The intimate relationship of the lipoma to the nerve roots and the absence of a distinct plane between tumor and spinal cord precluded a complete resection of this tumor. The consensus is that the goal of intervention is

decompression and generous debulking, following by a duraplasty with the fascia lata [1-5, 8]. The use of CO

laser and continuous somatosensory evoked potential (SEP) is very helpful.

M. Lee et al. [5] believe that patients with non- dysraphic intramedullary spinal cord lipoma are at high risk of developing irreversible neurological dysfunc- tion. Because intramedullary lipomas may replace nor- mal spinal cord tissue during embryonic development, surgical debulking of the lipoma prior to permanent spinal cord injury might have prevented the irreversible spinal cord dysfunction seen in many cases. The role of surgery in intramedullary spinal cord lipomas might be to stabilize and temporize the patient’s clinical course.

Since these patients do not usually improve after sur- gery, it might be advantageous for them to undergo early surgery before they become too debilitated.

Early diagnosis using MR imaging is easy. In future, we will use the diagnostic sensitivity and specificity of MR imaging for earlier diagnosis of intramedullary spinal cord lipoma and perform surgical debulking of the lesions prior to irreversible disease progression.

Patients in whom the intramedullary spinal cord lipoma is only partially resected should be informed that substantial weight gain or pregnancy may aggra- vate their symptoms. Corticosteroids, either endog- enously produced or exogenously administered, are implicated in the growth of lipomas in different ana- tomical locations, including the intramedullary space in the spinal cord causing cord compression. Agraha- rkar et al. [1] reported the first case of growth of intramedullary lipoma in a renal transplant recipient after steroid use.

CONCLUSION

Non-dysraphic intramedullary spinal cord lipoma can present in adulthood with symptoms of myelopathy as well as nonradicular pain. The surgical treatment of intramedullary spinal cord lipomas is very difficult and dangerous but it is the only way to protect patients from total paralysis and to improve their everyday comfort.

The goal of intervention is decompression and gener- ous debulking, followed by a duraplasty.

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