Solitary Parenchymal Calcification

Solitary Parenchymal Calcification

Anne G. Osborn, MD, FACR



  • Neurocysticercosis

  • Tuberculosis

  • Cavernous Malformation

  • Oligodendroglioma

  • Ganglioglioma

  • Diffuse Astrocytoma, Low Grade

  • Pilocytic Astrocytoma

Less Common

  • Arteriovenous Malformation

  • Ependymoma

  • Parasites, Miscellaneous

Rare but Important

  • Physiologic Calcification, Brain

  • “Brain Rock”

  • Calcified Embolus

  • Saccular Aneurysm

  • Metastasis, Parenchymal

  • TORCH Infection

  • DNET

  • Meningioangiomatosis


Key Differential Diagnosis Issues

  • Solitary brain calcification includes

    • True parenchymal calcification

    • Some lesions that may look like they are in brain itself but are not actually in parenchyma

      • Lesion in deep sulcus (neurocysticercus cyst)

      • Lesion in vessel (calcified embolus, saccular aneurysm)

  • Key question: Is Ca++ solitary focus or are there multiple calcified foci in solitary mass-like lesion?

  • Solitary “dot-like” or globular Ca++

    • Typically infectious (neurocysticercosis, TB, occasionally other rare parasites)

    • Less common

      • Physiologic (habenular commissure, unilateral basal ganglia)

      • Vascular (AVM, cavernous malformation, Ca++ embolus)

    • Rare = brain “rock”

  • Solitary mass-like lesion with clustered Ca++

    • Neoplasm (many)

    • Cavernous malformation

Helpful Clues for Common Diagnoses

  • Neurocysticercosis

    • Nodular calcified (healed) stage

    • Multiple (“starry sky”) > solitary lesions

    • Most NCC cysts are actually cisternal (within depths of superficial sulci) > brain parenchyma, ventricles

  • Tuberculosis

    • Healed granuloma

      • Can be single or multiple

      • Many fewer lesions than NCC

      • Occasionally solitary tuberculoma can be mass-like, mimic neoplasm

  • Cavernous Malformation

    • Solitary > multiple

    • Ca++ can be dot-like, clumped, or scattered within single lesion

    • Do MR with T2* scan (GRE, SWI) to look for hemorrhage, multiplicity

  • Oligodendroglioma

    • Cortical/subcortical mass

    • Slow-growing; may erode adjacent skull

    • 70-90% calcify (nodular, clumped)

    • Adult > child

  • Ganglioglioma

    • Slow-growing, cortically based neoplasm

    • Child/young adult with epilepsy

    • Common: Ca++ nodule, ± cysts

    • May erode/remodel adjacent skull

  • Diffuse Astrocytoma, Low Grade

    • Hemispheres > posterior fossa

    • Solid > > cystic mass

    • 10-20% calcify

    • Infiltrates brain

    • Intrinsic tendency to undergo malignant degeneration

  • Pilocytic Astrocytoma

    • Cerebellum > optic nerve/chiasm, 3rd ventricle > pons

    • Cyst with nodule (cerebellum)

    • Solid mass (optic chiasm/hypothalamus, pons)

    • Ca++, hemorrhage uncommon (unless pilomyxoid variant)

Helpful Clues for Less Common Diagnoses

  • Arteriovenous Malformation

    • Little/no mass effect unless hemorrhage

    • Look for enlarged feeding arteries, draining veins

    • Occasional Ca++ in nidus, draining veins (phlebolith)

  • Ependymoma

    • 3rd most common posterior fossa neoplasm in children (after medulloblastoma, pilocytic astrocytoma)

    • 2/3 infratentorial (4th ventricle)

    • 1/3 supratentorial (extra-ventricular, hemispheric WM)

      • Large, extensively calcified cystic/solid hemispheric mass in young child? Think ependymoma first!

    • 50% of all ependymomas calcify

    • Cysts, hemorrhage also common

  • Parasites, Miscellaneous

    • Except NCC, parenchymal Ca++ rare

    • Any healed parasitic infection can calcify

Helpful Clues for Rare Diagnoses

  • Physiologic Calcification, Brain

    • True solitary, unilateral normal parenchymal Ca++ unusual

      • Basal ganglia usually bilateral, occasionally unilateral

      • Habenular commissure may Ca++

  • “Brain Rock”

    • Dense globular parenchymal Ca++

    • No infection, neoplasm, degeneration

  • Calcified Embolus

    • In artery within sulcus, not brain parenchyma

  • Saccular Aneurysm

    • Huge, bizarre-appearing, extensively calcified mass in adult? Think partial/completely thrombosed giant saccular aneurysm

  • Metastasis, Parenchymal

    • Untreated metastases rarely calcify

    • Breast, mucinous carcinoma, osteosarcoma metastasis may calcify spontaneously

  • TORCH Infection

    • Multiple > > solitary

    • CMV most common

    • Cortical

  • DNET

    • Almost all patients < 20 years

    • Chronic epilepsy

    • Well-delineated, “bubbly” appearing cortical mass

      • May remodel overlying skull

      • Gross Ca++ uncommon, hemorrhage rare

      • < 20% enhance

      • May have adjacent cortical dysplasia

  • Meningioangiomatosis

    • Child/young adult with seizures

    • Hamartomatous cortical/leptomeningeal malformation

    • Meningovascular proliferation along perivascular spaces (PVSs)

    • 50% associated with neurofibromatosis

    • Cortical mass with Ca++ (often gyriform)

    • T2 hypointense

    • Plaque-like pial, linear enhancement along PVSs

Image Gallery

Axial NECT shows solitary calcified NCC cyst image, probably in depths of sulcus. This was an incidental finding in an immigrant from endemic area who has systemic NCC. No other brain lesions were identified.

Axial NECT shows small right medial frontal calcification image in a patient with known neurocysticercosis. Although lesion looks intraparenchymal, it is most likely within a deep sulcus.

(Left) Axial NECT in patient with known TB shows parenchymal calcification image with surrounding hypodensity, characteristic of healed caseating granuloma. (Right) Axial NECT shows large bifrontal densely calcified lesion image without mass effect. Note encephalomalacia image in adjacent parenchyma. Solitary tuberculoma was found at surgery.

Only gold members can continue reading. Log In or Register to continue

Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Solitary Parenchymal Calcification

Full access? Get Clinical Tree

Get Clinical Tree app for offline access