Case record...Intramedullary cavernoma

1. CASE OF THE WEEK
PROFESSOR YASSER METWALLY
CLINICAL PICTURE
CLINICAL PICTURE:
A 33 years old male patient presented with gradual progressive hemiplegia with a dorsal sensory level at D 4.
RADIOLOGICAL FINDINGS
RADIOLOGICAL FINDINGS:
Figure 1. Intramedullary cavernoma. On precontrast T1 images {A) mild dilatation of D5 spinal segment (opposite to D7
vertebral segment) is seen with a markedly hypointense pencil shaped oblong longitudinal center that extends through the
whole of the dilated spinal segment with two slightly hyperintense foci seen inside the hypointense longitudinal zone. On
postcontrast MRI T1 images {B,C) slight contrast enhancement is seen at the periphery of the hypointense zone and two
enhanced spots are seen inside the hypointense zone.
Figure 2. Intramedullary cavernoma. On
MRI T2 images the intramedullary
longitudinal lesion is seen of mixed
intensity with mild dilatation of the
affected spinal segment. The hypointense
longitudinal zone that is appreciated on
the MRI T1 images appears hyperintense
on the MRI T2 images with irregular
contour, This MRI T2 hyperintensity is
surrounded by MRI T2 hypointensity that
extends around the hyperintense core of
the lesion for a variable distance. The MRI
T2 mixed signal intensity is much
appreciated on cross sectional images. Also
notice the asymptomatic vertebral
hemangioma at D 8.

2. Figure 3. Intramedullary cavernoma.
On MRI T2 images (A,B) the
intramedullary longitudinal lesion is
seen of mixed intensity with mild
dilatation of the affected spinal
segment. The hypointense
longitudinal zone that is appreciated
on the MRI T1 (C,D) images appears
hyperintense on the MRI T2 images
with irregular contour, This MRI T2
hyperintensity is surrounded by MRI
T2 hypointensity that extends around
the hyperintense core of the lesion for
a variable distance. The MRI T2
mixed signal intensity is much
appreciated on cross sectional
images.
44
Figure 4. Intramedullary cavernoma. On MRI T2 images (B) the intramedullary longitudinal lesion is seen of mixed intensity
with mild dilatation of the affected spinal segment. The hypointense longitudinal zone that is appreciated on the MRI T1
images (A) appears hyperintense on the MRI T2 images with irregular contour, This MRI T2 hyperintensity is surrounded by
MRI T2 hypointensity that extends around the hyperintense core of the lesion for a variable distance. The MRI T2 mixed
signal intensity is much appreciated on cross sectional images. Also notice the asymptomatic vertebral hemangioma at D 8.

3. Figure 5. Intramedullary cavernoma. MRI T2 images (A,B) and precontrast MRI T1 images showing a mixed signal intensity
intramedullary lesion, The MRI mixed signal intensity of the precontrast MRI T1 images and the MRI T2 images is due to the
presence of altered blood of different ages.
 Conclusion
MRI picture of intramedullary cavernoma.
The MRI mixed signal intensity of the precontrast MRI T1 images and the MRI T2 images is due to the presence of altered
blood of different ages.
1. The MRI T1 precontrast hyperintensity is due to methemoglobin
2. The MRI T2 hypointensity is due to hemosiderin pigments.
Table 1. Evolution of MR imaging signal characteristics
Iron-containing Iron oxidation Red cell
Phase Time T1 T2 T2*
molecule state membranes
Hyperacute Hours Oxyhemoglobin Fe2+ Intact Hypointense Hyperintense
Acute Hours to days Deoxyhemoglobin Fe 2+ Intact iso/
Hypointense Hypointense
Hypointense
Early Days to 1 Methemoglobin Fe2+ Intact
Hyperintense Hypointense
subacute week
Late 1 week to Methemoglobin Fe2+ Degraded
Hyperintense Hyperintense
subacute months
Chronic >months Hemosiderin Fe2+ Degraded iso/
Hypointense Hypointense
Hypointense
Abbreviations: Fe, iron; iso, isointense relative to normal brain.
DIAGNOSIS:
DIAGNOSIS: INTRAMEDULLARY CAVERNOMA
DISCUSSION
DISCUSSION:
Although they are not considered vascular lesions in the Anson and Spetzler grading system because they do not shunt blood
and have no arterial feeders and draining veins, spinal cavernous malformations (spinal cavernoma) (SCM) are another cause
of treatable myelopathy. 1 The frequency of spinal cavernomas is difficult to ascertain because of the low number of spinal
cord autopsies. In 1976, Voigt and Yasargil could find only 164 cases of cavernous malformations (cavernoma) in the literature.
13 In anther review, Ghogawala and Ogilvy reported only 67 intramedullary spinal cavernomas in the English-language

4. literature. 18 With the development of CT scanning and particularly MR imaging, these lesions are being reported more often.
It is estimated that cavernomas have an incidence of between 0.02% and 4% in the population 8 and that 3% to 5% of
cavernomas occur in the spinal cord. 15 Spinal cavernous malformations are considered to be congenital lesions that may
enlarge with time. 8 They are slow-flow lesions without arteriovenous shunting. They are found throughout the cord and are
often intramedullary Unlike their intracranial counterparts, which have no gender preponderance, 70% of spinal cavernoma
occur in women. 56 Sporadic forms and familial forms with autosomal dominant inheritance with variable penetrance have
been described. 4,6,7
Clinical features of spinal cavernomas vary from acute to progressive to asymptomatic. 10 Ogilvy et al described four types of
clinical presentations: (1) acute episodes with stepwise neurologic decline, (2) acute onset of a neurologic deficit with rapid
neurologic deterioration, (3) acute onset of a mild neurologic deficit with gradual neurologic deterioration, and (4) slowly
progressive neurologic decline. 16
Acute symptoms are caused by hemorrhage, which may cause enlargement of the spinal cavernoma or hematomyelia. Patients
often present with sudden back pain, often at the level of the lesion. Neurologic defects may follow many hours after the attack
of pain. This delayed neurologic deterioration may help differentiate spinal cavernoma hemorrhages from those of spinal
AVMS.
The progressive course of spinal cavernomas could be caused by small microhemorrhages, which may cause enlargement of the
spinal cavernoma. Small hemorrhages with organization, capillary budding, and propagation and repetitive hemorrhages are
two possible reasons for progression. 8 Other theories for progressive neurologic decline include a neurotoxic effect from red
blood cell degradation or an effect on the spinal cord microcirculation. 8
On gross inspection, cavernomas are well-defined, red-to-purple, lobulated lesions often described as looking like a mulberry.
Microscopically, cavernomas are made up of enlarged capillaries or sinusoidal vascular spaces with a simple endothelial lining,
thin adventitia, and no elastic or smooth muscle fibers in its walls. Evidence of prior hemorrhage is commonly seen. The
surrounding tissue usually has gliosis and hemosiderin. Calcification of spinal cavernoma is rare. 5 Spinal cavernomas are not
pathologically distinguishable from their intracranial counterparts. 9
Because so few spinal cavernomas have been studied, the natural history of these lesions is not completely known. Management
of spinal cavernoma depends on the patient's clinical symptoms and age and on the characteristics of the lesion. 5,8 For
asymptomatic lesions, no treatment is currently advised. 5,8 Symptomatic lesions are often surgically explored because of the
risk of future neurologic deterioration. The hemorrhage rate for cerebral cavernomas has been estimated to be between 0.5%
and 1.0% per year. 16,17 Whether this rate is valid for spinal cavernomas is unclear. In a review of 57 symptomatic patients
with spinal cavernomas, Canavero et al, 3 suggested a hemorrhage rate of 1.6% per year. 13 As with any spinal vascular
malformation, postoperative outcome depends largely on the level of preoperative neurologic function. 12 Residual tumor is
often difficult to distinguish from postoperative changes. Recurrence of spinal cavernoma after total removal and negative
postoperative MR imaging has been mentioned in only one review. 8,17
 Imaging of Spinal Cavernous Malformations
As with other vascular lesions of the spine, MR imaging should be the first modality used to look for spinal cavernomas.
Cavernous malformations are considered to be one of the angiographically occult lesions, and spinal angiography has no role in
its diagnosis or treatment. Although spinal cavernoma can enlarge the cord, this enlargement is often not detected with
myelographic studies. 12
MR imaging appearances of spinal cavernoma are quite similar to cerebral cavernomas. On MR imaging spinal cavernomas
are round or oblong lesions with mixed signal intensity from different stages of red blood cell breakdown. Cavernous
malformations are often encircled by a dark hemosiderin ring that shows characteristic blooming on gradient- recalled images.
Labauge et al, 7 found gradient-echo sequences to be the most sensitive for detecting small cavernomas. There is usually no or
minimal enhancement with the administration of contrast. Surrounding edema can often be seen on T2-weighted images.
Whereas the MR imaging appearance is characteristic, it is not pathognomonic. Other vascular malformations or hemorrhagic
neoplasms may have a similar appearance. Also, some spinal cavernomas may be hidden by hemorrhage and not visualized on
MR imaging.

5. Figure 6. Spinal cavernous malformation. A, Sagittal Tl -weighted MR image of the cervical spine shows an area of
heterogeneous signal intensity (arrow) at the level of C6 with some increased signal seen extending caudally (open arrow). B,
Sagittal T2-weighted MR image demonstrates heterogeneous signal (arrow) with some decreased signal seen extending
caudally (open arrow), representing subacute hemorrhage. C, Axial Tl -weighted MR image at the level of C6 shows
intramedullary mixed signal in the left aspect of the spinal cord (arrow). D, Axial T2*-weighted gradient-recalled MR image at
the level of C6 demonstrates low signal with a small area of high signal (arrow).
SUMMARY
SUMMARY
Table 2. Pathological characteristics of cavernomas that differentiate them from arteriovenous malformation
 Cavernous angiomas (cavernomas) consist of enlarged capillaries with the following characteristics:
 Sinusoidal
 Single layer of endothelium
 Thin collagenous wall

6.  Lack of smooth muscle fibers and elastic fibers
 Capillaries are immediately adjacent to each other, with no intervening neural tissue.
 They typically are not associated with enlarged feeding arteries or draining veins, and blood flow is low or even
stagnated (cavernomas are angiographically occult).
 The surrounding parenchyma contains hemosiderin-laden macrophages and iron-laden glial cells.
 Grossly, they may range from soft to hard.
 Thrombosis, calcification, or ossification results in a harder lesion.
 Adjacent neural tissue may be affected, and small hemorrhages result in hemosiderin staining (iron salts may incite an
epileptogenic focus). Tissues also may be gliotic.
Figure 7. Histopathology. (A) Microscopic section (trichrome stain) shows a mass of closely apposed vessels of varying size. The
vessel walls have a variable thickness, and there is no intervening brain. (B) Whole mount (trichrome stain) of a CM of the
third ventricle shows a plexus of vessels with some intervening brain at the periphery.
Figure 8. Example of cavernomas, notice absence of feeding arteries or draining veins

7. Figure 9. Pontine cavernoma, notice absence of feeding
arteries or draining veins
Figure 10. For comparison, an arteriovenous malformation, notice the feeding arteries and the draining veins
 Addendum
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REFERENCES
References
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Neurological Institute Quarterly 8:2-8, 1992
2. Awad IA: Patients with spinal cord cavernous malformations are at an increased risk for multiple neuraxis cavernous
malformations [comment]. Neurosurgery 45:33,1999
3. Canavero S, Pagni C, Kornfield M, et al: Spinal intramedullary cavernous angiomas: A literature meta- analysis. Surg
Neurol 43:448-452,1995
4. Halbach VV, Higashida RT, Hiehima GB: Treatment of vertebral arteriovenous fistulas. AJR Am J Roentgenol 150:405-
412,1988
5. Hurst RW: Spinal vascular disorders. In Atlas SW (ed): Magnetic Resonance Imaging of the Brain and Spine, ed 2.
Philadelphia. Lippincott-Raven, 1996 pp 1387- 1412
6. Johnson PC, Wascher TM, Golfinos J, et al: Definition and pathologic features. In Awad IA, Barrow DL (eds):
Cavernous Malformations. Park Ridge, IL, American Association of Neurological Surgeons, 1993, pp 1-11
7. Labauge P, Labauge S, Levy C, et al: Hereditary cerebral cavernous angiomas: Clinical and genetic features in 57
French families. Lancet 352:1892-1897,1998
8. McCormick WF, Nofzinger JD: quot;Cryptickquot; vascular malformations of the central nervous system. J Neurosurg 24:865-
875, 1966
9. Mehmet KY, Wecht DA, Awad IA: Clinical spectrum and natural history of spinal vascular malformations. In Barrow
DL, Awad IA (eds): Spinal Vascular Malformations. Park Ridge, IL, American Association of Neurological Surgeons,
1999, pp 45-55
10. Ogilvy C, Louis D, Ojemann R: Intramedullary cavernous angiomas of the spinal cord: Clinical presentation,
pathological features, and surgical management. Neurosurgery 31:219-230,1992
11. Oldfield EH: Spinal vascular malformations. In Wilkins RH, Rengachary SS (eds): Neurosurgery, ed 2, vol 2. New York,
McGraw-Hill, 1996, pp 2541-2558
12. Vishteh GA, Zabramski JM, Spetzler RF: Patients with spinal cord cavernous malformations are at an increased risk
for multiple neuraxis cavernous malformations. Neurosurgery 45:30-32, 1999
13. Voigt K, Yasargil MG: Cerebral cavernous hemangiomas or cavernomas: Incidence, pathology, localization, diagnosis,
clinical features and treatment: Review of the literature and report of an unusual case. Neurochirurgia 19:59,1976
14. Wong JH, Awad IA: Spinal vascular malformations. In Jafar jj, Awad IA, Rosenwasser RH (eds): Vascular
Malformations of the Central Nervous System. Philadelphia, Lippincott Williams & Wilkins, 1999, pp 155-160
15. Zimmerman R, Spetzler R, Lee K, et al: Cavernous malformations of the brainstem. J Neurosurg 75:32- 39,1991
16. Ogilvy C, Louis D, Ojemann R: Intramedullary cavernous angiomas of the spinal cord: Clinical presentation,
pathological features, and surgical management. Neurosurgery 31:219-230,1992
17. Metwally, MYM: Textbook of neuroimaging, A CD-ROM publication, (Metwally, MYM editor) WEB-CD agency for
electronic publication, version 9.2a April 2008
18. Ghogawala Z, Ogilvy OS: Intramedullary cavernous malformations of the spinal cord. Neurosurg Clin North Am
10:101-109,1999