|Year : 2021 | Volume
| Issue : 6 | Page : 312-314
Thoracic intradural extramedullary lipomas
Liao Hsiang-Chih, Dueng-Yuan Hueng, Yuan-Hao Chen, Hsin-I Ma, Da-Tong Ju, Tang Chi-Tun
Department of Neurological Surgery, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
|Date of Submission||30-Aug-2020|
|Date of Decision||01-Dec-2020|
|Date of Acceptance||21-Mar-2021|
|Date of Web Publication||24-May-2021|
Dr. Tang Chi-Tun
No. 325, Sec. 2, Cheng-Kung Road, Neihu 114, Taipei
Source of Support: None, Conflict of Interest: None
Intradural extramedullary lipomas are rare congenital and histologically benign tumors that represent <1% of all spinal cord tumors. However, the indications for surgery and the degree of resection or decompression are under debate. We report on our experience with spinal decompression for the treatment of one intradural extramedullary thoracic lipomas.
Keywords: Intradural, extramedullary, lipoma, decompression
|How to cite this article:|
Hsiang-Chih L, Hueng DY, Chen YH, Ma HI, Ju DT, Chi-Tun T. Thoracic intradural extramedullary lipomas. J Med Sci 2021;41:312-4
| Introduction|| |
Intradural extramedullary lipomas are rare congenital and histologically benign tumors that represent <1% of all spinal cord tumors. Although reports in the literature have described intra and extramedullary lesions along the entire spinal axis, these tumors are most frequently observed in the lumbosacral area with spinal dysraphism. Intradural spinal lipomas of the cervical and thoracic cord are quite rare. The neurological features are characterized by a slowly progressive course of spastic paraparesis, tetraparesis, paresthesia, and pain. Experts believe that complete removal is not feasible because lipomas tend to exhibit no clear plane between the spinal cord and nerve roots. However, the indications for surgery and the degree of resection or decompression are under debate.
| Case Report|| |
A 44-year-old Taiwanese male presented with a 6-month history of refractory paresthesia predominantly on the right lower leg. In the preceding 6 months, symptoms had progressed considerably with poor heat and cold perception. Otherwise, his neurologic physical examination results were normal. No history of recent weight change was noted, and findings from plain X-rays of the lumbothoracic spine were also normal. Magnetic resonance imaging revealed an extramedullary mass resembling a lipomatous lesion between T10 and T12 that was ventrally compressing the spinal cord [Figure 1] and [Figure 2]. During surgery, wide laminectomies from T91 to L1 were performed. The dura mater swelled with tension due to the underlying lipoma. On entering the dura, the lipoma protruded posteriorly. With the exception of the lipoma, a relatively normal spinal cord was observed. Although some arachnoid adhesions to the underlying lipoma were identified, restoration of a free cerebrospinal fluid flow seemed possible. Finally, duroplasty with dural patch graft was performed to ensure adequate space for decompression. The wound was closed layer by layer. Postoperatively, the patient's paresthesia improved and he was discharged uneventfully. The patient presented no further neurological deficits. Here, we review the literature and discuss in detail the disease entity.
|Figure 1: One hyperintense lesion (white arrow) in the intradural space between T10 and T12 is observed on T1- and T2-weighted images|
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|Figure 2: Mass lesion exhibited signal drop on STIR (white arrow) image without overt contrast enhancement (black arrow) on T1-weighted images|
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| Discussion|| |
Spinal tumors can be classified into five categories according to the anatomic location: (a) intramedullary, (b) intradural extramedullary, (c) extradural, (d) radicular, and (e) filum terminale and cauda equina.
Our patient had an intradural extramedullary lipoma. These lesions are likely to develop in the cervicothoracic, thoracic, or cauda equina regions but may also involve the entire length of the cord. When they occur in the lumbosacral region, they are associated with spinal dysraphism. The pathogenesis of lipoma is proposed as follows: (a) metaplasia of the adipose tissue between the pia and arachnoid membrane, (b) proliferation of fat cells, which reside in the pia mater, and (c) proliferation from inclusions of embryonic rests within the meninges. Despite the benign nature of spinal lipomas, numerous researchers have claimed that radical resections are difficult and increase morbidity because adhesions exist between lipoma and the spinal cord. Most of these lesions extend over several spinal levels and reach a critical volume.
The necessity of spinal lipoma removal, and even the feasibility of prophylactic resection, should be carefully evaluated. A study by PierreKahn et al. on 291 lumbosacral lipomas concluded that the surgical benefit for lipomas of the filum terminale was more obvious than that for lipomas of the conus medullaris. Surgical complications were also more severe in the conus medullaris group. Similarly, we can apply this conclusion to lipomas of the thoracic cord.
In our patient, progressive neurological symptoms were present; therefore, surgery was indicated. The best surgical principle for removing lesions remains under debate. Few researchers have suggested a more radical surgical removal approach because such strategies are associated with higher postoperative morbidity rates. Most researchers advocate partial removal to decompress the spinal cord and root. The general consensus is that the compression or tethering of the spinal cord and roots explain the clinical symptoms; therefore, the therapeutic objectives should involve decompression and untethering of the spinal cord. Chronic compression of the thoracic cord by this sizeable mass was sufficient to explain the neurological symptoms, which were comparable to other long-standing compression syndromes leading to thoracic myelopathy. Therefore, decompression of the cord was required, and partial resection, laminectomy, and duroplasty were performed.
| Conclusion|| |
Attempts to decrease the size or even to remove a lipoma are not always possible and might not be required to achieve satisfactory results. Such interventions also pose considerable risks of postoperative complication. We recommend debulking surgery if minimal adhesion is present, or partial resection when extensive adhesion is observed, to decompress the affected spinal levels through laminectomy and duropalsty. However, the optimal surgical strategies for treating spinal intradural lipomas are rationally individualized.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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Pierre-Kahn A, Zerah M, Renier D, Cinalli G, Saint-Rose C, Lellouch-Tubiana A, et al
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[Figure 1], [Figure 2]