Cavernous Malformation¶
Definition¶
A spinal cavernous malformation (cavernoma) is a low-flow vascular lesion composed of thin-walled, endothelium-lined vascular channels without intervening neural tissue. Unlike AVMs, cavernous malformations are angiographically occult — they are not visible on catheter angiography because of their low flow. They can occur within the cord (intramedullary) or, less commonly, in the extradural or intradural extramedullary compartments.
Imaging Findings¶
MRI¶
- "Popcorn" or "mulberry" appearance — Mixed-signal lesion on T1 and T2 due to blood products of different ages within the loculated channels
- Complete hemosiderin rim — A low T2/GRE signal ring surrounding the lesion, representing chronic hemosiderin deposition from repeated microhemorrhages. This rim is the most characteristic feature.
- No flow voids — Unlike AVMs, cavernous malformations do not have flow voids (they are low-flow)
- No significant edema (unless recent hemorrhage)
- No enhancement (or minimal enhancement)
- GRE/SWI — Most sensitive sequence; the hemosiderin rim and internal blood products "bloom" on susceptibility-weighted sequences
- Size — Variable, usually <2 cm
CT¶
- May show calcification
- Often occult on CT
Angiography¶
- Angiographically occult — Not visible on catheter angiography (distinguishes from AVM)
Clinical Pearl
The complete hemosiderin rim on T2/GRE is the hallmark of cavernous malformation and distinguishes it from other intramedullary lesions. An ependymoma may have a hemosiderin "cap" at its poles, but it also shows a well-defined enhancing solid component — cavernous malformations show the "popcorn" appearance with a complete rim and no significant enhancement. GRE/SWI is the most sensitive sequence and should be included in any spine MRI protocol for suspected vascular lesions.
Management¶
- Observation — For asymptomatic lesions discovered incidentally
- Surgical excision — For lesions causing progressive neurological deficit or recurrent hemorrhage, if surgically accessible
- Radiosurgery is generally not effective for spinal cavernous malformations
Key Points¶
- Low-flow vascular lesion, angiographically occult
- "Popcorn" appearance with a complete hemosiderin rim on T2/GRE is diagnostic
- No flow voids, no significant enhancement
- GRE/SWI is the most sensitive sequence
- Presents with recurrent hemorrhage or progressive myelopathy
- Surgical excision for symptomatic or accessible lesions
References¶
- Spinal cord cavernous malformation. Radiopaedia.org. https://radiopaedia.org/articles/spinal-cord-cavernous-malformation
- Caton MT, Karsonovich T, Shenoy VS. Cerebral Cavernous Malformations. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2025 Jan 21. https://www.ncbi.nlm.nih.gov/books/NBK538144/
- Panda A, Diehn FE, Kim DK, et al. Spinal Cord Cavernous Malformations: MRI Commonly Shows Adjacent Intramedullary Hemorrhage. J Neuroimaging. 2020;30(5):690-696. https://pubmed.ncbi.nlm.nih.gov/32462668/
- Mabray MC, Starcevich J, Hallstrom J, et al. High Prevalence of Spinal Cord Cavernous Malformations in the Familial Cerebral Cavernous Malformations Type 1 Cohort. AJNR Am J Neuroradiol. 2020;41(6):1126-1130. https://pubmed.ncbi.nlm.nih.gov/32467184/
- Rios-Zermeno J, Ghaith AK, Navarro-Garcia de Llano JP, et al. Surgical versus conservative management of spinal cord cavernous malformations: a systematic review and comparative meta-analysis. J Neurosurg Spine. 2025;42(4):509-519. https://pubmed.ncbi.nlm.nih.gov/39889295/
- Ohnishi YI, Nakajima N, Takenaka T, et al. Conservative and Surgical Management of Spinal Cord Cavernous Malformations. World Neurosurg X. 2020;5:100066. https://pubmed.ncbi.nlm.nih.gov/31891154/