Intraventricular Calcification(s)

Karen L. Salzman, MD

DIFFERENTIAL DIAGNOSIS

Common

Physiologic Calcification, Choroid Plexus
Choroid Plexus Cyst
Neurocysticercosis
Neurofibromatosis Type 2
Tuberous Sclerosis Complex

Less Common

Meningioma
Ependymoma
Intraventricular Hemorrhage (Mimic)
Choroid Plexus Papilloma
Subependymal Giant Cell Astrocytoma
Subependymoma
Central Neurocytoma
Cavernous Malformation
TORCH, General (Mimic)

Rare but Important

Medulloblastoma (PNET-MB)
Choroid Plexus Carcinoma
Craniopharyngioma

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Majority of intraventricular Ca++ are benign, related to normal aging or choroid plexus cysts; almost always bilateral
Benign intraventricular Ca++ are almost always associated with choroid plexus glomi
If unilateral Ca++, consider underlying mass
If extensive choroid plexus Ca++ in child is seen, consider NF-2

Helpful Clues for Common Diagnoses

Physiologic Calcification, Choroid Plexus
- Choroid plexus is calcified in majority of adults by age 40
- In children, approximately 5% by age 15
Choroid Plexus Cyst
- Common incidental finding in older patients (40% prevalence)
- Irregular, peripheral Ca++ in majority of adult cases; usually bilateral
- Most common cause of choroid plexus mass in adults is benign degenerative cyst (xanthogranulomatous)
Neurocysticercosis
- Imaging varies with development stage, host response
  - Nodular calcified (healed) stage: Small, Ca++ nodules
- Typically subarachnoid spaces; may involve cisterns > parenchyma > ventricles
- Intraventricular cysts are often isolated; 4th ventricle most common
- Most common cause of cerebral Ca++ under 30 years
Neurofibromatosis Type 2
- Nonneoplastic cerebral Ca++ is uncommon manifestation
- Extensive choroid plexus Ca++ > cortical surface Ca++ > ventricular lining Ca++
Tuberous Sclerosis Complex
- Ca++ subependymal nodules (SEN), 98% of patients
  - Along caudothalamic groove > atrial > > temporal
  - 30-80% of SEN enhance, best seen on MR
- Cortical/subcortical tubers, WM lesions 70-95%

Helpful Clues for Less Common Diagnoses

Meningioma
- Calcified (20-25%): Diffuse, focal, sand-like, sunburst, globular, rim
- Approximately 1% are intraventricular
- Most common in left lateral ventricle
Ependymoma
- Soft or “plastic” tumor: Squeezes out through 4th ventricle foramina
- Ca++ common (50%)
- 2/3rd infratentorial, arise from floor of 4th
- Hydrocephalus common; ± cysts, hemorrhage
Intraventricular Hemorrhage (Mimic)
- Typically associated with trauma
- May be primary presentation of AVM
- Acutely, hyperdense blood may mimic intraventricular Ca++
- May result in Ca++ in chronic phase
Choroid Plexus Papilloma
- Intraventricular, papillary neoplasm derived from choroid plexus epithelium
- Child with strongly enhancing, lobulated intraventricular mass; Ca++ in 25%
- 50-70% → atrium of lateral ventricle
- 4th ventricle most common site in adults
Subependymal Giant Cell Astrocytoma
- Enhancing mass at foramen of Monro
- Ca++ common; hydrocephalus common
- Occurs in 15% of TSC patients
Subependymoma
- Rare, benign, well-differentiated, and intraventricular, ependymal tumor
- T2 hyperintense lobular, nonenhancing intraventricular mass
- May see cysts, hemorrhage, Ca++
- Inferior 4th (60%) > lateral ventricle
Central Neurocytoma
- Typical “bubbly” appearance; Ca++ common
- Lateral ventricle, attached to septum pellucidum
- Moderate to strong enhancement
Cavernous Malformation
- Rarely intraventricular, 2.5-11% of cases
- Ca++ & T2 hypointense hemosiderin rim common
- Enhancement variable
TORCH, General (Mimic)
- Acronym for congenital infections caused by transplacental transmission of pathogens
- Toxo, CMV, HIV, & rubella cause parenchymal &/or periventricular Ca++