Tectal (Quadrigeminal Plate) Lesion



Tectal (Quadrigeminal Plate) Lesion


Karen L. Salzman, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Diffuse Astrocytoma, Low Grade


  • Brainstem Glioma, Pediatric


Less Common



  • Lipoma


  • Neurofibromatosis Type 1


  • Chiari 2


Rare but Important



  • Cavernous Malformation


  • Progressive Supranuclear Palsy


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Tectum is dorsal portion of midbrain, dorsal to cerebral aqueduct


  • Tectum includes superior & inferior colliculi & periaqueductal gray matter


Helpful Clues for Common Diagnoses



  • Diffuse Astrocytoma, Low Grade



    • Nonenhancing T2 hyperintense mass


    • Supratentorial 2/3, infratentorial 1/3


    • 50% of “brainstem gliomas” are diffuse astrocytomas


  • Brainstem Glioma, Pediatric



    • Heterogeneous group of gliomas


    • Tectal glioma: Most indolent, often only need CSF diversion



      • Expands tectum & obstructs aqueduct


      • T2 hyperintense mass ± enhancement


Helpful Clues for Less Common Diagnoses



  • Lipoma



    • Well-delineated lobulated extra-axial mass with fat attenuation/intensity


    • Interhemispheric fissure most common location (30-40%)


    • 20-25% pineal region (attached to tectum)


  • Neurofibromatosis Type 1



    • Focal areas of signal intensity (FASI) in white matter & deep gray matter



      • Typically involve globus pallidus


      • May involve brainstem


    • Tectal gliomas are associated with NF1


  • Chiari 2



    • Complex malformation of hindbrain associated with neural tube closure defect, usually lumbar myelomeningocele


    • Small posterior fossa, “beaked” tectum


    • “Towering” cerebellum protrudes up through incisura, compresses tectum


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Tectal (Quadrigeminal Plate) Lesion

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