Multiple Parenchymal Calcifications



Multiple Parenchymal Calcifications


Anne G. Osborn, MD, FACR



DIFFERENTIAL DIAGNOSIS


Common



  • Normal


  • Neurocysticercosis


  • Cavernous Malformation (Multiple)


Less Common



  • Tuberculosis


  • Tuberous Sclerosis Complex


  • Sturge-Weber Syndrome


  • Metastases, Parenchymal


Rare but Important



  • Remote Brain Injury


  • Opportunistic Infection, AIDS


  • TORCH Infections


  • Lymphocytic Choriomeningitis


  • Metabolic (Inherited or Acquired)



    • Fahr Disease


    • MELAS


    • Hypothyroidism


    • Hyperparathyroidism


    • Hypoparathyroidism


    • Pseudohypoparathyroidism


    • X-Linked Adrenoleukodystrophy


  • Pseudo-TORCH Syndromes


  • Radiation and Chemotherapy


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Discrete, multifocal/scattered Ca++


  • Hyperdensities on NECT, variably “blooming” hypointensities on T2*/GRE


  • Location helpful in differential diagnosis



    • Basal ganglia (physiologic in adults)



      • Abnormal Ca++ can be congenital, acquired


      • End result of toxic/metabolic (e.g., thyroid/parathyroid disorder), inflammatory/infectious etiologies (e.g., TORCH)


    • Cortex: Neurocysticercosis (sulci), TB, Sturge-Weber


    • Gray-white junction



      • Fahr disease


      • Tuberous sclerosis complex


      • Metastases (treated > > untreated)


      • Radiation/chemotherapy


    • Periventricular



      • Fahr disease


      • TORCH, pseudo-TORCH


      • Tuberous sclerosis complex


Helpful Clues for Common Diagnoses



  • Normal



    • Microscopic brain Ca++ (“calcospherocytes”)



      • Ca++, iron deposits in microvessels


      • Common in elderly, especially basal ganglia (BG)


      • Except for BG, macroscopic brain parenchymal calcifications usually abnormal


    • Basal ganglia



      • Ca++ common in adults


      • Physiologic > > metabolic derangement (e.g., thyroid/parathyroid disorders)


      • Uni-/bilateral


      • Symmetric or asymmetric


  • Neurocysticercosis



    • Nodular calcified stage of neurocysticercosis (NCC)


    • Multiple, small (“starry sky” pattern) > solitary, large Ca++


    • Lesions appear to be parenchymal but most actually in depths of sulci!


  • Cavernous Malformation (Multiple)



    • Multiple (familial) CM syndrome


    • 10-30% of cases


    • Variably-sized hyperdense/Ca++ lesions



      • Can be small/almost invisible, occasionally very large


      • Homogeneous or “salt and pepper”


    • T2* (SWI > GRE) best to detect


Helpful Clues for Less Common Diagnoses



  • Tuberculosis



    • Ca++ uncommon (≈ 20%)



      • Represents healed granuloma


      • Solitary > multiple small Ca++ more common


      • Ca++ often somewhat larger (can be giant) compared to NCC


      • Few scattered, larger Ca++ (TB) vs. numerous multiple small (NCC)


    • “Target sign” = central Ca++ surrounded by enhancing rim


  • Tuberous Sclerosis Complex



    • 98% have Ca++ subependymal nodules



      • Most along caudothalamic groove


      • 30-80% enhance


      • Enhancing lesion near foramen of Monro needs follow-up (growth indicates subependymal giant cell astrocytoma)



    • Tubers in cortex, subcortical white matter



      • Up to 50% show some Ca++ by age 10


      • Enhancement less common (10-15%), does not presage malignancy


  • Sturge-Weber Syndrome



    • Gyral (cortex, subcortical white matter) Ca++ (not in pial angioma!)


    • Atrophy/prominent subarachnoid spaces


    • Look for enlarged, enhancing ipsilateral choroid plexus, prominent medullary veins


    • 20% bilateral


  • Metastases, Parenchymal



    • Typically post-treatment (e.g., XRT for breast metastases)


    • Untreated metastases rarely Ca++


    • Exceptions



      • Mucinous adenocarcinoma


      • Malignant bone neoplasms


      • Breast (rare)


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Multiple Parenchymal Calcifications

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