Multiple Enhancing Lesions, General



Multiple Enhancing Lesions, General


Karen L. Salzman, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Metastases, Parenchymal


  • Multiple Sclerosis


  • Neurocysticercosis


  • Abscess (Multiple)


Less Common



  • ADEM


  • Opportunistic Infection, AIDS


  • Tuberculosis


  • Lymphoma, Primary CNS


  • Neurosarcoid


  • Glioblastoma Multiforme


Rare but Important



  • Vasculitis


  • Lyme Disease


  • Lymphoma, Intravascular (Angiocentric)


  • Parasites, Miscellaneous


  • Susac Syndrome


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Superficial enhancement is usually vascular or inflammatory


  • Nodular cortical/subcortical enhancement is characteristic for hematogenous metastases & embolic disease


  • Ring-enhancing lesions have numerous etiologies: Gliomas (40%), metastases (30%), abscesses (8%), demyelinating disease (6%)


  • Thick, irregular (“shaggy”) rim-enhancing lesions are usually malignant


  • DWI MR may help differentiate lesions


Helpful Clues for Common Diagnoses



  • Metastases, Parenchymal



    • Discrete enhancing parenchymal masses at gray-white interface


    • Account for up to 50% of all brain tumors


    • 80% hemispheres, 15% cerebellum, 3% basal ganglia (BG)


    • Enhancement: Punctate, solid, or ring


    • Primary tumor often known


  • Multiple Sclerosis



    • Multifocal periventricular & callososeptal T2 hyperintensities in a young adult


    • Active demyelination enhances transiently


    • Incomplete ring or “horseshoe shaped” enhancement is classic



      • May be nodular, ring, or semilunar


  • Neurocysticercosis



    • Cyst with scolex in convexity subarachnoid spaces is typical


    • Four stages: Vesicular, colloidal vesicular, granular nodular, nodular calcified


    • Vesicular: No enhancement typical; may see discrete, eccentric scolex enhancement


    • Colloidal vesicular: Thick cyst wall enhances; enhancing marginal nodule


    • Granular nodular: Thickened, retracted cyst; nodular or ring enhancement


    • Nodular calcified: Small calcified lesion, rare minimal enhancement


  • Abscess (Multiple)



    • DWI + & T2 hypointense rim classic


    • Four stages: Early cerebritis, late cerebritis, early capsule, late capsule


    • Early cerebritis: No/patchy enhancement


    • Late cerebritis: Intense but irregular rim enhancement


    • Early capsule: Well-defined, thin-walled enhancing rim thicker on side near cortex


    • Late capsule: Cavity collapses, thickened enhancement of capsule especially side near cortex


    • Septic emboli → multiple lesions


Helpful Clues for Less Common Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Multiple Enhancing Lesions, General

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