Neurol India Home 
 

LETTER TO EDITOR
Year : 2016  |  Volume : 64  |  Issue : 4  |  Page : 821--823

Cavernous malformation in the conus medullaris: A rare report

Ram Kumar Goyal, Biswaranjan Nayak, Rajiv Maharshi, Debabrata Biswal 
 Department of Neurosurgery, Apollo Hospitals, Bhubaneswar, Odisha, India

Correspondence Address:
Ram Kumar Goyal
Department of Neurosurgery, Apollo Hospitals, Bhubaneswar, Odisha
India




How to cite this article:
Goyal RK, Nayak B, Maharshi R, Biswal D. Cavernous malformation in the conus medullaris: A rare report.Neurol India 2016;64:821-823


How to cite this URL:
Goyal RK, Nayak B, Maharshi R, Biswal D. Cavernous malformation in the conus medullaris: A rare report. Neurol India [serial online] 2016 [cited 2020 Oct 23 ];64:821-823
Available from: https://www.neurologyindia.com/text.asp?2016/64/4/821/185416


Full Text

Sir,

Cavernous malformations (CMs) of the central nervous system are defined as abnormally dilated blood vessels, lined by a thin endothelium without intervening normal nervous tissue. Spinal CMs account for 5–12% of all spinal vascular lesions.[1] Intramedullary CMs are very rare. CMs in the conus medullaris account for 4% of all intramedullary spinal CMs.[2] The male:female ratio varies from 1:1 to 1:3 in various studies.[2] Patients become clinically symptomatic during the third and fourth decade of life.[1] These lesions are usually solitary but in about 27% cases, they are associated with intracranial CMs.[2] The usual clinical presentation is pain, weakness, sensory deficit and bladder/bowel dysfunction. Since the advent of magnetic resonance imaging (MRI), only few cases of this relatively rare lesion have been reported. Here, we describe the clinical, neuroradiological, and surgical features of a case of intramedullary CM in the conus medullaris of the spinal cord.

A 45-year-old woman presented with chief complaints of gradually progressive low back pain, urinary incontinence, and constipation for 1 year. She had tingling and numbness in both her lower limbs (more in the soles) for the last 8 months. There was no history of diabetes mellitus or hypertension. She was taking medical treatment for back pain. History revealed urosurgical intervention in the form of sling procedure for urinary incontinence, but she did not improve. Neurological examination revealed a sensory deficit in the S1, S2, and S3 dermatomes and diminished bilateral ankle reflexes. Lumbar spine magnetic resonance imaging (MRI) revealed a well-circumscribed, rounded intramedullary lesion of heterogeneous signal intensity in the conus region of spinal cord with a low signal intensity rim on T2-weighted images [Figure 1]. We planned for surgical excision of the tumor. She underwent a D12 laminectomy. The dura was split in a linear fashion (4 cm), and the spinal cord was exposed. The conus was incised in the mid-line. A well-circumscribed dark-bluish lesion, measuring 1.0 cm × 0.5 cm in diameter, was revealed deep within the spinal cord. It was a malformed, tortuous vascular mass with areas of necrosis and hemosiderin deposition. The total mass was removed without disturbing the surrounding tissue. The operative impression was that of a CM. Histological examination revealed the tissue comprising of dilated, thin-walled veins with hemorrhagic areas and hemosiderin-laden macrophages. Verhoeff–Van Gieson staining suggested the venous nature of the vessels [Figure 2]. The postoperative course was uneventful and the sensory deficits improved. Bladder/bowel function became normal in 3-month follow-up.{Figure 1}{Figure 2}

A spinal intramedullary CM was first reported on autopsy in 1903, in a 35-year-old female patient. This lesion, located at the L1 level, had bled.[3] Its first successful excision was performed in 1912.[4] Cosgrove et al., presented the first surgical series of five patients harboring a CM in 1988.[5] Among the intramedullary CMs, the cervicomedullary junction was involved in 8%, cervical region in 32%, thoracic region in 54%, lumbar region in 3%, and conus medullaris in 3%.[1] Canavero et al., reported four lumbar CMs in a series of 55 patients.[6] Pagni et al., in a review of the literature, reported three CMs of the conus medullaris (in 28 intramedullary cases).[7] Khalatbari et al., in a review found that only nine cases had been reported in literature until 2011.[8] Most cases are described in adults, and only one case has been reported in the pediatric age group. A mini review of case reports is shown in [Table 1].{Table 1}

Spinal CMs are characterized by closely approximated, abnormal, dilated thin-walled sinusoidal spaces, lined by a single layer of endothelium and lacking an intervening nervous tissue.[9] The presentation is usually in the third and fourth decades of life. Reports of familial incidence and co-occurrence with intracranial CMs, suggest the possibility of genetic mechanisms in the development of such lesions.[10] These vascular malformations are slow-growing lesions, and may enlarge either by the occurrence of small hemorrhages followed by hemosiderin deposition or by the growth of its nidus.

Four patterns of clinical presentation have been described [Table 2].[1] The most frequent mode of presentation is that of progressive neurological decline. The usual clinical features are pain, weakness, sensory deficit, and bladder/bowel dysfunction. Progressive neurological deterioration can be confused with demyelinating pathologies, myelitis, intramedullary tumors, and spinal arteriovenous malformation. Hemosiderin is supposed to exert a neurotoxic effect and alter the surrounding microcirculation and, therefore, plays a role in the progression of symptoms.{Table 2}

CMs are angiographically occult vascular malformations, and MRI is the investigation of choice for the diagnosis of this condition. In addition, the period between the onset of symptoms and diagnosis depends on the pattern of presentation.

The appropriate treatment depends on the understanding of its natural history, including the annual rate of hemorrhage and the clinical outcome of treatment. It has been shown that the annual rate of hemorrhage of intramedullary spinal cord CMs (ISCCMs) ranges from 1.7% to 4.5%.[2],[11] Badhiwala et al., in a meta-analysis, supported its surgical resection as the management of choice for symptomatic patients.[12] Early surgery with total removal of the malformation should be the goal when approaching these spinal lesions before enlargement or rebleeding can occur.

Mitha et al.,[13] published a report of three operative approaches to ISCCMs: Posterior, posterolateral, and lateral. Of these, the posterior approach is the one most commonly used, especially for dorsal or central CMs. Intraoperative somatosensory and motor-evoked potential monitoring is used. A laminectomy or hemilaminectomy is performed over the appropriate spinal level, and the dura is opened. Often, CM can be localized on the basis of appearance of the dorsal pial surface, which reveals an exophytic lesion, blue-purple discoloration, and/or bulging of the cord surface. In such cases, a myelotomy is made directly over the lesion. The traditional approach to deep-seated ISCCMs without surface abnormalities is a midline myelotomy. Good results have also been reported by utilizing various localization techniques to guide in deciding the level of myelotomy, including the intraoperative ultrasonography and indocyanine green videoangiography.[12] Other options for more ventral or lateral lesions include a myelotomy through the dorsal root entry zone, anterolateral partial vertebrectomy or corpectomy, and radical facetectomy and dentate ligament resection. At the lesion site, a gliotic plane between the CM and the spinal cord usually facilitates the removal of the lesion. A subtotal resection should be considered when neurological function is at risk.

Conus medullaris CMs are very rare lesions. Appropriate neurological evaluation, and hence, an early diagnosis and proper treatment can prevent rebleeding, enlargement of the lesion, and dangerous clinical consequences associated with the lesion.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Ogilvy CS, Louis DN, Ojemann RG. Intramedullary cavernous angiomas of the spinal cord: Clinical presentation, pathological features, and surgical management. Neurosurgery 1992;31:219-29.
2Gross BA, Du R, Popp AJ, Day AL. Intramedullary spinal cord cavernous malformations. Neurosurg Focus 2010;29:E14.
3Hadlich R. A case of cavernous tumor of spinal cord with special reference to recent theories about the genes of cavernomas. Virchows Arch 1903;172:429-44.
4Schultze F. Further contribution to diagnosis and surgical treatment of tumors of the spinal cord: Successful operation of an intramedullary tumor. Dtsch Med Wochenschr 1912;38:1676-9.
5Cosgrove GR, Bertrand G, Fontaine S, Robitaille Y, Melanson D. Cavernous angiomas of the spinal cord. J Neurosurg 1988;68:31-6.
6Canavero S, Pagni CA, Duca S, Bradac GB. Spinal intramedullary cavernous angiomas: A literature meta-analysis. Surg Neurol 1994;41:381-8.
7Pagni CA, Canavero S, Forni M. Report of a cavernoma of the cauda equina and review of the literature. Surg Neurol 1990;33:124-31.
8Khalatbari MR, Hamidi M, Moharamzad Y. Pediatric intramedullary cavernous malformation of the conus medullaris: Case report and review of the literature. Child's Nerv Syst 2011;27:507-11.
9Jellinger K. Vascular malformations of the central nervous system: A morphological overview. Neurosurg Rev 1986;9:177-216.
10Lee ST, Choi KW, Yeo HT, Kim JW, Ki CS, Cho YD. Identification of an Arg35X mutation in the PDCD10 gene in a patient with cerebral and multiple spinal cavernous malformations. J Neurol Sci 2008;267:177-81.
11Jallo GI, Freed D, Zareck M, Epstein F, Kothbauer KF. Clinical presentation and optimal management for intramedullary cavernous malformations. Neurosurg Focus 2006;21:e10.
12Badhiwala JH, Farrokhyar F, Alhazzani W, Yarascavitch B, Aref M, Algird A, et al. Surgical outcomes and natural history of intramedullary spinal cord cavernous malformations: A single-center series and meta-analysis of individual patient data. J Neurosurg Spine 2014;21:662-76.
13Mitha AP, Turner JD, Spetzler RF. Surgical approaches to intramedullary cavernous malformations of the spinal cord. Neurosurgery 2011;68:317-24.