Nervous System Disorders
= CAVERNOUS ANGIOMA OF BRAIN = CAVERNOUS HEMANGIOMA = CAVERNOMA
= benign vascular hamartoma of immature blood vessels + intralesional hemorrhage
Cause: sporadic + solitary (⅔); hereditary + multiple (⅓)
Prevalence: 0.2–0.4% of general population
Associated with: ? developmental venous anomaly
Path: well-circumscribed nodule of honeycomblike dilated endothelial lined spaces separated by fibrous collagenous bands WITHOUT intervening neural tissue
Age: any; 3rd–6th decade (most common); M = F
- asymptomatic (most)
- Most common asymptomatic vascular malformation!
- headache, seizures (commonly presenting symptom), neurologic deficit (15%)
Location: cerebrum (mainly superficial subcortical in close contact with subarachnoid space / ventricles) >pons >cerebellum; solitary >multiple
- NO obvious mass effect / edema
- usually contain blood degradation products of different stages
- slow blood flow in vascular channels
NECT:
- small round / lobulated hyperdense region (CLUE)
- minimal surrounding edema
- extensive calcifications = hemangioma calcificans (20%)
CECT:
- none / minimal / intense enhancement
- low-attenuation areas due to thrombosed portions
MR (DIAGNOSTIC):
- typically popcorn appearance with bright lobulated center on T1WI + T2WI
- well-defined area of mixed signal intensity centrally (= “mulberry”-shaped lesion) with a mixture of:
- increased signal intensity (= extracellular methemoglobin / slow blood flow / thrombosis)
- decreased intensity (= deoxyhemoglobin / intracellular methemoglobin / hemosiderin / calcification)
- surrounded by hypointense rim (= hemosiderin) on T2WI
Angio:
- negative = “cryptic / occult vascular malformation”
Cx: hemorrhage of varying age
Risk of hemorrhage: 0.4–3.1% (4.3–6.5%) per year for sporadic (familial) cases
Rx: none; microsurgery (if symptomatic)
DDx:
- Hemorrhagic neoplasm (edema, mass effect)
- Hypertensive hemorrhage
- Small AVM (thrombosed / small feeding vessels, associated hemorrhage)
- Capillary telangiectasia / angioma (no difference)