Journal of Neuroimaging Vol 12 No 4 October 2002
Sheehan et al: Cavernomas With Bilateral Venous Angiomas

Development of a Posterior Fossa
Cavernous Malformation Associated
With Bilateral Venous Anomalies:
Case Report
ABSTRACT
Venous angiomas (VAs) and cavernous malformations (CMs) are common cerebrovascular malformations. Frequently, these lesions are
found in close proximity. The interrelationship between VAs and CMs
has not yet been adequately defined. The authors report a case of a 48year-old man with progressive dysarthria, dysmetria, and ataxia. Eight
years previously, magnetic resonance imaging (MRI) revealed a solitary
CM and bilateral posterior fossa VAs. Later imaging after neurological
progression revealed the presence of 2 rather than 1 CM adjacent to the
VAs. The sequential imaging suggests a causal relationship between
VAs and some CMs. Furthermore, the detailed MRI permitted
radiosurgical treatment of these CMs. The occurrence of de novo CMs
adjacent to VAs on future imaging studies in other patients may help
confirm the etiology of at least a subset of CMs.
Key Words: Cavernous malformation, venous angiomas,
radiosurgery.
Sheehan J, Lunsford LD, Kondziolka D, Flickinger J.
Development of a posterior fossa
cavernous malformation associated
with bilateral venous anomalies: case report
J Neuroimaging 2002;12:371-373.
DOI: 10.1177/105122802237978

The association between cavernous malformations (CMs) and
venous angiomas (VAs) is not uncommon.1 The etiology of these
vascular malformations and their interrelationship, however,
remain the subject of much debate.2-5 Magnetic resonance imaging (MRI) has become an important tool for identifying these
lesions, shedding light on the behavior and possible etiology of
their frequent association and making radiosurgical targeting
more precise.

Jason Sheehan, MD, PhD
L. Dade Lunsford, MD
Douglas Kondziolka, MD
John Flickinger, MD

Over the next 7 years, the patient had progression of his
dysarthria, right arm dysmetria, and gait ataxia. MRI now
revealed 2 CMs: 1 located in the right superior aspect of the
pons, at the pontomesencephalic junction (Fig 1), and the other
in the right dentate region of the cerebellum (Fig 2). MRI also
revealed evidence of bilateral venous anomalies in the cerebellar hemispheres (Figs 3, 4).
After discussing various options with the patient, including
further observation with repeat imaging, surgical resection, and
radiosurgery, the decision was made to treat both of the CMs
with gamma knife radiosurgery.6,7 We did not recommend additional observation because of the progressive nature of the
patient’s neurological symptoms as well as the chance for a hemorrhage that could result in neurological devastation. Surgical
resection of both CMs would have been fraught with difficulties,
including brainstem injury, cranial nerve palsies, worsening cerebellar dysfunction, and venous infarct as a result of damage to
the adjacent VAs. During stereotactic planning, the anomalous
venous drainage was excluded from the radiosurgical field. At 6
months after radiosurgery, the patient has improved articulation
and right arm coordination.

Discussion
Venous anomalies are known to be the most common
intracranial vascular malformation in both autopsy and clinical
series.1 VAs are believed to result from abnormal venous
embryogenesis and are sometimes referred to as developmental
anomalies.2 CMs were also believed to be congenital in nature.5
In recent years, an association between CMs and VAs has often
been reported.2,8,9 There appears to be an increased tendency
for hemorrhage in CMs associated with venous anomalies as opposed to CMs alone.8,9 Some have postulated that higher pressure due to restricted venous disease may cause hemorrhage
from a VA with subsequent formation of CMs.2,3,8,9 One case of
CM development was postulated to have occurred as a result of

Received April 1, 2002, and in revised form May 30, 2002. Accepted for publication June 3, 2002.

Case Presentation
The patient was a 48-year-old right-handed man with progressive gait and speech difficulties. The symptoms dated back to
1993. At that time, an MRI study including T1, T2, and gradient
echo sequences was obtained using an MRI with a 1.5-T field
strength and subsequently reviewed at that time by both a
neuroradiologist and a neurosurgeon. This MRI revealed a solitary pontomesencephalic CM in close proximity to bilateral
VAs. He was originally told that this was a “congenital lesion”
and would not require any further attention. Of note, the patient
had no significant past medical or family history, and he had no
prior surgeries.

From the Department of Neurological Surgery ( JS, LDL, DK)
and the Department of Radiation Oncology ( JF), Center for Image Guided Surgery, University of Pittsburgh Medical Center,
Presbyterian Hospital; and the Department of Neurological Surgery, University of Virginia, Health Sciences Center, Charlottesville ( JS).
Address correspondence to Jason Sheehan, Box 800-212, Department of Neurosurgery, Health Sciences Center, Charlottesville, VA 22908. E-mail: jps2f@virginia.edu.

Copyright © 2002 by the American Society of Neuroimaging

371

Fig 3. Sagittal magnetic resonance imaging (TR = 450, TE = 14
with gadolinium) illustrating the midbrain cavernous malformation in
close proximity to the venous anomalies.
Fig 1. Axial magnetic resonance imaging (TR = 21, TE = 7 with
gadolinium) revealing a cavernous malformation within the superior
aspect of the pons at the pontomesencephalic junction and bilateral
venous anomalies.

Fig 4. Axial magnetic resonance venogram reconstruction (TR =
21, TE = 7) depicting both the extensive bilateral cerebellar venous
anomalies and the adjacent cavernous malformation.

Fig 2.

Axial magnetic resonance imaging (TR = 21, TE = 7 with
gadolinium) depicting the deep cerebellar cavernous malformation
not seen on imaging 7 years previously.

increased venous pressure induced by radiation therapy.8 Little
et al10 demonstrated communication of CMs with the venous
circulation and thereby highlighted the close relationship be-

372

Journal of Neuroimaging Vol 12 No 4 October 2002

tween these vascular malformations. Comey et al11 noted
parenchymal enhancement associated with combined cavernous and venous malformations and postulated that venous hypertension and blood brain barrier disruption are associated
with selected venous malformations.
Others have theorized that VAs may facilitate formation of
CMs via angiogenic growth factor release and red blood cell

diapedesis.4 Pluripotential cells may also be present in zones of
active angiogenesis and demonstrate neoproliferation into the
walls of cavernomas.2,12,13 The development of a second CM on
follow-up imaging within the drainage region of bilateral VAs
supports the notion that some CMs are acquired vascular
lesions. This is the first case report to illustrate progressive CM
occurrence adjacent to bilateral posterior fossa VAs. The intimate relationship depicted on MRI between the bilateral
venous anomalies and CMs certainly suggests that the presence
of one type of malformation could have led to the formation of
the other. Although these images do not provide definitive proof
of a causal relationship between VA-induced venous hypertension and the de novo formation of CMs, we believe that they
provide an imaging correlate to the likely microscopic and biochemical factors linking these two types of cerebrovascular malformations. The fact that at least some CMs may be acquired
lesions highlights the need for further investigation into the
development and behavior of these vascular malformations.
With modern neuroimaging, many VAs and CMs are incidentally discovered. However, patients can frequently present
with headaches, seizures, disequilibrium, subarachnoid hemorrhage, and parenchymal hemorrhage. The annual risk of hemorrhage for these lesions is less than 1%.5,6 As such, surgical
intervention is generally reserved for patients with progressive
neurological deficit or recurrent hemorrhage. Surgical resection
of CMs can be curative. For those CMs not amenable to a conventional surgical approach, stereotactic radiosurgery has been
shown to reduce the risk of hemorrhage.6,7,14,15 In addition to
protecting against hemorrhage, radiosurgery also appears to
shrink the lesion and reduce the incidence of seizures associated
with some supratentorial CMs. 7,14 When treated with
radiosurgery, the venous anomalies are left outside of the
radiosurgical field.
The presence of 2 CMs in close proximity to bilateral posterior fossa VAs hints at the complex interrelationship between
these cerebrovascular malformations. Future imaging correlates
may help further elucidate the etiology of these lesions. Conventional angiography is typically unable to adequately depict these
vascular malformations. The ability of MRI and the relatively
recent adaptations of magnetic resonance venography to delineate these lesions have further accentuated these imaging
modalities. Moreover, detailed MRI facilitates the effective
treatment of these lesions with radiosurgery.

References
1. Griffin C, DeLaPaz R, Enzmann D. Magnetic resonance
appearance of slow flow vascular malformations of the
brainstem. Neuroradiology 1987;29:506-511.

2. Awad IA, Robinson JR, Mohanty S, Estes ML. Mixed vascular malformations of the brain: clinical and pathogenetic
considerations. Neurosurgery 1993;33:179-188.
3. McCormick PW, Spetzler RF, Johnson PC, Drayer BP. Cerebellar hemorrhage associated with capillary telangiectasia
and venous angioma: a case report. Surg Neurol 1993;39:451457.
4. Ciricillo SF, Dillon WP, Fink ME, Edwards MS. Progression of multiple cryptic vascular malformations associated
with anomalous venous drainage. Case report. J Neurosurg
1994;81:477-481.
5. Kupersmith MJ, Kalish H, Epstein F, et al. Natural history of
brainstem cavernous malformations. Neurosurgery
2001;48:47-54.
6. Kondziolka D, Lunsford LD, Flickinger JC, Kestle JR.
Reduction of hemorrhage risk after stereotactic
radiosurgery for cavernous malformations. J Neurosurg
1995;83:825-831.
7. Zhang N, Pan L, Wang BJ, Wang EM, Dai JZ, Cai PW.
Gamma knife radiosurgery for cavernous hemangiomas. J
Neurosurg 2000;93(suppl 3):74-77.
8. Maeder P, Gudinchet F, Meuli R, de Tribolet N. Development of a cavernous malformation of the brain. Am J
Neuroradiol 1998;19:1141-1145.
9. Abdulrauf SI, Kaynar MY, Awad IA. A comparison of the
clinical profile of cavernous malformations with and without associated venous malformations. Neurosurgery
1999;44:41-47.
10. Little JR, Awad IA, Jones SC, Ebrahim ZY. Vascular pressures and cortical blood flow in cavernous malformation of
the brain. J Neurosurg 1990;73:555-559.
11. Comey C H, Kondziolka D, Yonas H. Regional
parenchymal enhancement with mixed cavernous/venous
malformations of the brain. J Neurosurg 1997;86:154-158.
12. Harris FJ, Jakobiec FA. Cavernous hemangioma of the
orbit. J Neurosurg 1979;51:219-228.
13. Hood CI. Cavernous hemangioma of the orbit. A consideration of pathogenesis with an illustrative case. Arch
Ophthalmol 1970;83:49-53.
14. Amin-Hanjani S, Ogilvy CS, Candia GJ, Lyons S, Chapman
PH. Stereotactic radiosurgery for cavernous malformations:
Kjellberg’s experience with proton beam therapy in 98 cases
at the Harvard Cyclotron. Neurosurgery 1998;42:1229-1236.
15. Mitchell P, Hodgson TJ, Seaman S, Kemeny AA, Forster
DM. Stereotactic radiosurgery and the risk of haemorrhage
from cavernous malformations. Br J Neurosurgery
2000;14:96-100.

Sheehan et al: Cavernomas With Bilateral Venous Angiomas

373