Multiple Hypointense Foci on T2



Multiple Hypointense Foci on T2


Nancy J. Fischbein, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Neoplasm



    • Lymphoma


    • Metastases, Parenchymal


    • Multifocal Glioma


  • Atypical Infection



    • Bacterial (TB, Nocardia)


    • Fungal Diseases


    • Toxoplasmosis, Acquired


Less Common



  • Neurosarcoid


  • Neoplasm-like Conditions



    • Post-Transplant Lymphoproliferative Disorder (PTLD)


    • Lymphomatoid Granulomatosis


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • These lesions show mild T2 hypointensity or “intermediate” signal intensity (SI)



    • Lesions are often isodense or mildly hyperdense to gray matter (GM) on CT


  • Lesions in this ddx often associated with vasogenic edema & “bright” on T2/FLAIR, but are centrally iso- or hypointense to GM


  • Neoplasms included are generally small round blue-cell tumors (e.g., lymphoma) or highly cellular metastases with high nuclear-to-cytoplasmic ratio


  • DWI variable; may be mildly reduced due to ↑ cellularity of some of these lesions


Helpful Clues for Common Diagnoses



  • Lymphoma



    • Both primary & secondary CNS lymphoma may present as intermediate SI masses



      • PCNSL often limited to brain parenchyma


      • SCNSL more likely to involve leptomeninges, dura, bone


  • Metastases, Parenchymal



    • Highly cellular, non-necrotic metastases


    • Breast & lung mets often T2 intermediate


  • Atypical Infection



    • Pyogenic abscesses typically have central ↑ SI on T2WI because of pus


    • Atypical non-pyogenic “abscesses” often have intermediate SI on T2WI



      • In TB, due to caseous material


      • Fungal: Due to absence of pus, concentration of paramagnetic ions


      • Toxo: May show “eccentric target sign”


    • Variable reduced diffusion


Helpful Clues for Less Common Diagnoses



  • Neurosarcoid



    • Parenchymal nodules & masses often intermediate T2 SI due to high cellularity


    • Look for dural/leptomeningeal disease


  • Post-Transplant Lymphoproliferative Disorder (PTLD)



    • Parenchymal lesions resemble lymphoma


  • Lymphomatoid Granulomatosis



    • Rare lymphoproliferative disorder


    • Typical: Punctate & linear enhancement


    • Large coalescent nodules T2 intermediate

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

Related posts:

Falx Lesions Sulcal/Cisternal Enhancement Solitary Hyperdense Parenchymal Lesion Bithalamic Lesions Fusiform Arterial Enlargement Enlarged Neural Foramen

Stay updated, free articles. Join our Telegram channel
Tags:
Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Multiple Hypointense Foci on T2

Full access? Get Clinical Tree
Get Clinical Tree app for offline access