Cavernous Malformation (Cavernoma) with associated Deep Venous Anomaly (DVA)

Oscar Cisneros MD, Razia Rehmani MD

Key points:

• Cavernomas are common cerebral vascular malformations which are often asymptomatic.
• Solitary lesions are common. Multiple lesions indicate familial predisposition such as seen with Familial Multiple Cavernous Malformation Syndrome. Screening of family members may be indicated.
• Risk of hemorrhage is 1% per year for familial cases and somewhat less for sporadic lesions.
• Cavernomas and capillary telangiectasias are commonly seen after cerebral radiotherapy.
• Cavernomas can undergo recurrent hemorrhage and may have characteristic popcorn ball–like appearance.^1–3
• Cavernomas can be concurrently seen with DVA’s in 20% (range 2-40%) in which case they are known as mixed vascular malformation6.
• An associated cavernous angioma is commonly seen in patients with DVA in whom an intracerebral hemorrhage has been diagnosed.^1,2,4
• Cavernomas are usually supratentorial (80%) but can be found anywhere.

Differential Diagnosis: Includes causes for intracranial microhemorrhages.

Smaller lesions:
• Cerebral amyloid angiopathy
• Chronic hypertensive encephalopathy.
• Cerebral vasculitis
• Radiation induced vasculopathy
• Hemorrhagic metastases
• Diffuse Axonal Injury (DAI)
• Neurocysticercosis and Tuberculoma (for calcified lesions)

Larger lesions:
• Hemorrhagic primary brain tumors (e.g. ependymoma, glioblastoma)
• Hemorrhagic metastasis

Discussion:

Cavernous malformations are congenital or acquired vascular anomalies that occur in approximately 0.5% of the general population. Patients are usually asymptomatic but may present after acute or recurrent hemorrhage usually around 40-60 years of age. Initial presenting features may include seizures, headaches and neurologic deficits.^1,8,9 MRI is considered the most sensitive and specific modality for detecting cavernomas.² It has been described that up to 55% of patients will have an affected relative. A study in Hispanic-American Kindreds showed strong evidence favoring linkage of cavernous malformation to a segment of 7q in all families.⁷

Cavernomas tend to be supratentorial (80%) and usually solitary. One third of patients with sporadic lesions may have more than one. Larger lesions appear as foci of hyperdensity on CT. However, smaller lesions may not be seen on initial CT, unless there has been recent bleed in which case edema may be seen around the lesion.
On MRI, they are best seen on Gradient echo (GRE) or susceptibility weighted imaging (SWI) than spin echo sequences. They have characteristic popcorn ball-like appearance with low-signal-intensity rim due to hemosiderin deposition.^1–3,9 Subacute hemorrhage and degraded blood products within the lesion produce a halo of signal hyperintensity around the lesion on T-1 weighted images, this being useful for differentiating cavernomas from other intracranial hemorrhages.⁹ These lesions do not enhance, although enhancement is possible. These lesions are angiographically occult.

Cavernomas can be concurrently seen with DVA’s in 20% (range 2-40%) in which case they are known as mixed vascular malformation6. They are now considered to be the most common cerebral vascular malformation accounting for 55% of all cases in this era of post contrast cross-sectional imaging. DVAs are a slow-flow venous anomaly consisting of numerous dilated medullary veins converging into a single vein forming the classic caput medusa or palm tree appearance, which in turn drains into a dural sinus or ependymal vein. DVA drains normal brain. DVAs are usually incidental findings but may present with intracranial hemorrhage with vague neurologic symptoms such as headache or dizziness. The cause of cerebral hemorrhage in patients with DVAs is usually attributed to the cavernoma.

Dystrophic calcifications may be seen in upto 30% of cases. DVA’s demonstrate the classic appearance on postcontrast MRI and CT. Susceptibility weighted imaging is the preferred sequence for low flow venous anomalies. Angiography also demonstrates the classic caput medusae appearance during the venous phase with normal arterial phase and no shunting. No differential diagnosis is usually offered since DVA tend to have a classic appearance.

Isolated DVA’s requires no treatment. Asymptomatic cavernoma’s can be treated conservatively. Symptomatic cases presenting with hemorrhage, edema with resultant mass effect and epileptic activity may require surgery. In these symptomatic cases when possible, complete resection is curative. The current established indications for surgical management are overt hemorrhage, focal neurologic symptoms, and/or medically intractable epilepsy. It is imperative to inform the surgeon of the presence of associated DVA, since cauterization of collecting vein can result in venous infarct of the area of brain being drained.

References:

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10. The New England Journal of Medicine Downloaded from nejm.org at MOUNT SINAI SCHOOL OF MEDICINE on August 14, 2012. For personal use only. No other uses without permission. From the NEJM Archive. Copyright © 2010 Massachusetts Medical Society. All rights r. 2010:2015. doi:10.1056/NEJM199401273300403

Authors

Oscar Cisneros, MD

PGY 2 Internal Medicine Resident
St Barnabas Health System
Bronx, NY

Razia Rehmani, MD

Chief of Neuroradiology & Musculoskeletal Imaging
Diagnostic Radiology
St Barnabas Health System
Bronx, New York