Focal Cortical Mass



Focal Cortical Mass


James D. Eastwood, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Cerebral Ischemia-Infarction, Acute (Cortical)


  • Metastases, Parenchymal


  • Oligodendroglioma


  • Cerebritis


  • Diffuse Astrocytoma, Low Grade


Less Common



  • Venous Infarction


  • Pleomorphic Xanthoastrocytoma


  • Tuberous Sclerosis Complex


  • Pachygyria-Polymicrogyria (Focal Cortical Dysplasia)


  • DNET


  • Ganglioglioma


Rare but Important



  • Pilocytic Astrocytoma


  • Cavernous Malformation


  • Desmoplastic Infantile Ganglioglioma


  • Viral Encephalitis


  • Astroblastoma


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Is the mass enhancing or not?


  • Is there vasogenic edema?


  • Does part or all the mass contain low ADC values?


  • Is the lesion solitary or multiple?


  • Are bilateral lesions present?


  • Lesions in this differential are primarily related to tumor, ischemia, & infection


Helpful Clues for Common Diagnoses



  • Cerebral Ischemia-Infarction, Acute (Cortical)



    • Often wedge-shaped, involve both gray & white matter (WM)


    • Bright on T2, FLAIR, & DWI with low ADC values


    • Typically seen in vascular territories


    • Usually a unilateral process; can be bilateral when there is a central source of multiple emboli (i.e., cardiac disease)


  • Metastases, Parenchymal



    • Often occur at gray-white junctions


    • Enhancing mass with surrounding vasogenic edema


    • Usually solid, may be complex with central cystic or necrotic areas


    • May be hemorrhagic with increased T1 SI


    • May be solitary but frequently are multiple & bilateral


  • Oligodendroglioma



    • T2 hyperintense mass, variable enhancement


    • Calcification is common


    • Frontal > other lobes; usually a single mass


  • Cerebritis



    • Gray & white matter are often involved together


    • T2 hyperintense with variable enhancement & variable DWI appearance


    • Cerebritis essentially represents a developing brain abscess & is commonly caused by pyogenic bacteria


    • May be solitary or multifocal


  • Diffuse Astrocytoma, Low Grade



    • T2 hyperintense WM mass, may involve gray matter


    • May mimic stroke; however ADC values typically normal to elevated


    • No or minimal enhancement is typical


    • Usually a solitary mass


    • Bilateral disease may be seen in gliomatosis cerebri, a rare infiltrative process


Helpful Clues for Less Common Diagnoses



  • Venous Infarction



    • T2 hyperintense lesion


    • Associated hemorrhage is very common, often at gray-white junctions


    • Typically related to dural sinus thrombosis


    • May be multiple & bilateral if the superior sagittal sinus is involved


  • Pleomorphic Xanthoastrocytoma



    • Cortical enhancing mass with adjacent cyst, classic appearance


    • Enhancement extends to meninges, causing a “dural tail”


    • Temporal lobe is most common location


    • Occurs in young adults


  • Tuberous Sclerosis Complex



    • Multiple cortical “tubers” = cortical hamartomas are T2 hyperintense & nonenhancing


    • Calcified subependymal nodules ± enhancing giant cell astrocytoma at the foramen of Monro is classic


    • Usually a multiple & bilateral process



    • When solitary, consider Taylor cortical dysplasia


  • Pachygyria-Polymicrogyria (Focal Cortical Dysplasia)



    • Limited to gray matter; focal or regional thickening of the cortex


    • Variable T2 appearance; no enhancement


    • Many have deep sulci with thickened cortex that mimics a mass


    • Occasionally a linear region of increased T2 signal connects the focal cortical dysplasia with the ependymal surface


  • DNET



    • Multicystic cortical mass, frequently seen in the temporal lobe


    • “Bubbly” appearance classic


    • Variable enhancement


    • Solitary lesion in a young adult typical


  • Ganglioglioma



    • Enhancing (multi)cystic mass; may be solid or have a cyst & nodule appearance


    • Calcification is common


    • Temporal lobe is most common location


    • Solitary lesion


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Focal Cortical Mass

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