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ESSENTIAL INFORMATION

Key Differential Diagnosis Issues
- Is patient asymptomatic?
- Is calcification physiologic or pathologic? - Physiologic - Vascular: Age-related changes of atherosclerotic vascular disease (ASVD) common - Dural: Petroclinoid ligament often calcified - Pathologic - Look for associated mass in/around sella, cavernous sinus
- Anatomic sublocation important - Dura (cavernous sinus, tentorium, petroclinoid ligaments) calcifies but less often than falx - Arteries, cavernous, and suparclinoid internal carotid artery (ICA) Ca⁺⁺ common - Pituitary, infundibulum, hypothalamus almost never show physiologic Ca⁺⁺
Helpful Clues for Common Diagnoses
- Vascular Calcification - Juxtasellar dura, vessels, not brain
- Atherosclerosis, Intracranial - Some age-related ASVD Ca⁺⁺ normal, physiologic - Strong relationship between carotid stenosis and stroke risk (NASCET criteria) - Thickness of Ca⁺⁺ plaque does not correlate directly with luminal stenosis - Dense, globular Ca⁺⁺ may be more significant than mural/laminar - Some authors suggest high grade of cavernous ICA Ca⁺⁺ correlates with small (not large) vessel ischemia - Carotid intraplaque hemorrhage is independent risk factor for acute stroke
- Saccular Aneurysm - Supra-/juxtasellar > intracavernous - Mural Ca⁺⁺ common - Ca⁺⁺ may be rim or globular - Aneurysm often partially/completely thrombosed - CTA/MRA key for accurate diagnosis - Pulsation artifact may be seen on MR
- Meningioma - Ca⁺⁺ in 20-25%; pattern highly variable - Diffuse or focal - Solid (brain rock) or scattered - Psammomatous (sand-like) or sunburst > globular > rim - Look for dural tail - Look for changes in adjacent planum sphenoidale and clinoid processes (hyperostosis) - Can cause blistering, hyperostosis, hypertrophied ethmoid or sphenoid sinuses (pneumosinus dilatans)
- Craniopharyngioma - Adamantinomatous craniopharyngioma - 90% cystic, 90% Ca⁺⁺ (rim, globular), 90% enhance - Bimodal age distribution: 5-15 years and 45-60 years - Papillary craniopharyngioma - Solid mass with variable globular Ca⁺⁺, enhancement - Typically adults
- Neurocysticercosis - Healed racemose neurocysticercosis (NCC) in basal cisterns may show Ca⁺⁺ - Cisternal NCC, often racemose (lobulated, grape-like), lacking scolex - Typically occurs in high convexity subarachnoid spaces - May involve cisterns > parenchyma > ventricles
Helpful Clues for Less Common Diagnoses
- Dermoid Cyst - Sellar/parasellar/frontonasal region most common site - Unilocular fat-like cyst - Look for "droplets" in sulci, cisterns (ruptured dermoid) - 20% have capsular Ca⁺⁺
- Astrocytoma - Pilocytic a****strocytoma - Common in optic chiasm/hypothalamus/3rd ventricle (2nd most common location after cerebellum) - Enhancement varies (none to striking) - Ca⁺⁺ uncommon in supratentorial pilocytic astrocytomas - WHO grade 1 - Pilomyxoid astrocytoma - Rare tumor; commonly hypothalamic/chiasmatic region - Hemorrhage common - Affects infants and young children - Ca⁺⁺ uncommon - Astrocytoma, IDH-mutant - May calcify but uncommon in this location - T2 hyperintense - No enhancement - WHO grades 2-4 - Chordoid glioma - WHO grade 2, rare tumor - Hypothalamus/anterior 3rd ventricle mass - Ovoid, well circumscribed - Usually solid mass; may have associated cysts (rare) - Hyperdense on NECT; Ca⁺⁺ variable - Isointense on T1-, iso- to mildly hyperintense on T2WI - Enhances strongly, usually uniformly
- Arteriovenous Malformation - Supra-/juxtasellar < hemispheres - 25-30% have Ca⁺⁺ - Pial vascular malformation of brain - Artery to vein shunting without intervening capillary bed - MR: Tangle or serpiginous flow voids, "bag of worms"
Helpful Clues for Rare Diagnoses
- Cavernous Malformation - Ca⁺⁺ common; popcorn or mulberry appearance - Cerebral hemispheres most common location - Hypothalamus, juxtasellar lesions uncommon - May be associated with adjacent developmental venous anomaly - Contains masses of closely apposed immature blood vessels
- Chondrosarcoma, Skull Base - Center at petrooccipital fissure - 50% have chondroid Ca⁺⁺ in tumor matrix (arcs, rings) - T2 hyperintense, high ADC value (≥ 2.0 x 10⁻³ mm²/sec) - Enhance strongly, heterogeneously - Whorls of enhancing lines within tumor matrix
- Chordoma, Clivus - 35% arise in skull base - Center at sphenooccipital synchondrosis - Destructive, invasive clivus mass - CT: 50% contain ossific fragments of destroyed bone - T2 hyperintense; heterogeneous enhancement
- Pituitary Macroadenoma - Most common lesion in this location - Only 1-2% Ca⁺⁺ - Can be very invasive, destructive
- Rathke Cleft Cyst - Only 10-15% Ca⁺⁺ vs. > 90% of craniopharyngioma - Calcified Rathke cleft cyst may be indistinguishable from craniopharyngioma - No enhancement of cyst - Normal pituitary often wraps around cyst: Claw sign
- Benign Nonmeningothelial Tumors - Rare cause of juxtasellar Ca⁺⁺ - Chondroma: Occurs along sella/parasellar most common; dura/falx rare - Expansile, lobulated soft tissue mass - Curvilinear matrix Ca⁺⁺ - Osteochondroma: Usually arises from skull base; dura/falx rare - May see Ca⁺⁺ matrix in cap atop cortical bone - Parent bone contiguous with cortex of osteochondroma - Osteoma: Usually arises from outer table of calvarium, rarely inner table - Dense lesion without diploic involvement
- Osteosarcoma, Skull Base - Osteolytic or blastic lesions with soft tissue mass and ill-defined margins - Tumor Ca⁺⁺ may be sunburst - Heterogeneous enhancement

References

Selected References

Images

Selected Images

Physiologic Calcification, Dura Axial NECT bone window shows dural calcifications along the petroclinoid ligaments. Although typically physiologic, multiple dural calcifications may also be seen in basal cell nevus syndrome.

Atherosclerosis, Intracranial Coronal NECT shows atherosclerotic calcifications along the walls of the bilateral intracranial ICAs and left MCA . Intracranial atherosclerosis often involves the intracranial internal carotid and vertebral arteries. There is often mural calcification and decreased vessel caliber.

Saccular Aneurysm Axial NECT shows scattered subarachnoid hemorrhage within the interhemispheric and sylvian fissures. A rounded hypodense lesion with peripheral calcification in the left suprasellar cistern is the causative ruptured saccular ICA aneurysm.

Meningioma Axial CECT shows an extensive plaque-like calcification along the optic nerve sheath and left anterolateral cavernous sinus related to a meningioma. Strong, homogeneous enhancement is typical following contrast administration.

Craniopharyngioma Coronal NECT shows a complex cystic/solid mass with internal hemorrhage and calcifications in the sella and suprasellar regions related to craniopharyngioma. This mass results in obstructive hydrocephalus .

Dermoid Cyst Coronal NECT shows a complex cystic sellar/parasellar mass with internal fat and peripheral calcification compatible with a dermoid cyst. Fat within the subarachnoid spaces are related to prior rupture, which may result in a chemical meningitis.

Pilomyxoid Astrocytoma Axial NECT shows calcification in a hypothalamic/suprasellar mass in a 12-year-old child. A pilomyxoid subtype of pilocytic astrocytoma was diagnosed at surgery. These rare tumors often occur in the hypothalamic region.

Chordoid Glioma Axial NECT in this 48-year-old with progressive visual decline shows a hyperdense suprasellar mass with globular calcifications . Preoperative diagnosis was papillary craniopharyngioma. Chordoid glioma was diagnosed at surgery.

Arteriovenous Malformation Axial NECT shows a slightly hyperdense calcified mass in the right medial temporal lobe. CECT scans showed typical findings of arteriovenous malformation.

Cavernous Malformation Axial NECT shows a very large, partially calcified mass extending inferiorly from the ventricles into the hypothalamus. Cavernous malformations are benign vascular hamartomas that most commonly occur in the hemispheres.

Chondrosarcoma, Skull Base Axial NECT bone window shows a destructive central skull base mass with internal chondroid matrix in this case of chondrosarcoma. These masses typically arise from the petrooccipital fissure.

Chordoma, Clivus Sagittal CECT shows a destructive lesion of the central skull base with rim calcification and fragments of residual bone. There is significant associated mass effect on the brainstem , typical of clival chordomas. These malignant tumors have a high recurrence rate.

Pituitary Macroadenoma Axial NECT shows a large, lobulated, hyperdense suprasellar mass . This invasive macroadenoma extended into the posterior paranasal sinuses and along the anterior pons with focal calcification . Only 1-2% of macroadenomas calcify.

Chondroma Coronal CECT shows an intrasellar mass with dense globular calcification , typical of benign chondroma. No stalk was found connecting the chondroma to parent bone. (Courtesy L. Cromwell, MD.)

Additional Images

Meningioma Axial NECT shows marked hyperostosis of the anterior clinoid process and the posterior clinoid process related to a suprasellar meningioma. These WHO grade I tumors are very common in the parasellar region and may mimic a pituitary adenoma.

Dermoid Cyst Axial NECT shows a mass with fat-debris level extending from the suprasellar cistern into the sylvian fissure. Note calcification and fat droplets in CSF from a ruptured dermoid.

Physiologic Calcification, Dura Axial bone CT shows physiologic calcification in both cavernous internal carotid arteries as well as the dura of the cavernous sinus wall and both petroclinoid ligaments .

Saccular Aneurysm Axial NECT shows a subarachnoid hemorrhage from a partially thrombosed, calcified basilar tip aneurysm.

Chondrosarcoma, Skull Base Axial bone CT shows a large partially calcified mass extending from the skull base into the sella, causing obstruction of the sphenoid sinus .

Osteochondroma Sagittal bone CT reconstructed from axial data shows globular intra- and suprasellar calcification in cartilaginous cap of an osteochondroma arising from cortex of dorsum sellae .

Osteochondroma Axial T2WI MR in same case as prior CT shows very hypointense mass above dorsum sellae. NECT scan showed dense calcifications within a tumor cap characteristic for osteochondroma.

Craniopharyngioma Axial NECT shows rim and globular calcification in a multicystic suprasellar mass in child. Note fluid-fluid level . Most calcified suprasellar masses in children are craniopharyngiomas.

Neurocysticercosis Axial NECT shows punctate Ca⁺⁺ in the suprasellar and ambient cisterns from chronic racemose cysticercosis. (Courtesy E. Bravo, MD.)

Pituitary Macroadenoma Coronal CECT shows a large, lobulated, calcified , intra- and suprasellar mass that encases the right internal carotid artery . Only 1-2% of macroadenomas calcify.

Chordoid Glioma Axial NECT in this 48 year old with progressive visual decline shows hyperdense suprasellar mass with globular calcifications . Pre-operative diagnosis was papillary subtype of craniopharyngioma. Chordoid glioma of 3rd ventricle was found at surgery.

Chordoma, Clivus Axial CECT shows destructive lesion of central skull base encasing both internal carotid arteries and containing flecks of residual bone or calcifications .

Atherosclerosis, Intracranial Axial NECT shows prominent calcific changes in both supraclinoid internal carotid arteries caused by atherosclerosis. Intracranial atherosclerosis often involves the distal basilar artery and the cavernous and supraclinoid internal carotid arteries. There is often mural calcification and decreased vessel caliber.

Saccular Aneurysm Axial CECT shows a giant, mostly thrombosed, saccular aneurysm. Note the ring enhancement of the thrombosed segment of the aneurysm as well as globular and rim calcification. CTA or MRA is key for making an accurate preoperative diagnosis.

Craniopharyngioma Axial NECT shows rim and globular calcification in a cystic suprasellar mass in a 7-year-old child. Most calcified suprasellar masses in children are craniopharyngiomas. This craniopharyngioma also showed enhancement on postcontrast images.

30 KiB Raw Blame History

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Helpful Clues for Common Diagnoses

Helpful Clues for Less Common Diagnoses

Helpful Clues for Rare Diagnoses