Bony Lesion, Aggressive



Bony Lesion, Aggressive


Lubdha M. Shah, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Metastases, Lytic Osseous


  • Metastases, Blastic Osseous


  • Lymphoma


  • Multiple Myeloma


  • Osteomyelitis, Pyogenic


  • Osteomyelitis, Granulomatous


Less Common



  • Degenerative Endplate Changes


  • Accelerated Degeneration


  • Schmorl Node


  • Langerhans Cell Histiocytosis


Rare but Important



  • Spondyloarthropathy, Hemodialysis


  • Neurogenic (Charcot) Arthropathy


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Bone destruction (tumor, infection) vs. remodeling, short transition zone (degenerative disc disease)


Helpful Clues for Common Diagnoses



  • Metastases, Lytic Osseous



    • Lytic, permeative diffusely enhancing lesion destroys posterior cortex & pedicle


    • T1 hypointense/T2 hypo ⇒ hyperintense, T2 hyperintense rim surrounding hypointense met


  • Metastases, Blastic Osseous



    • Sclerotic lesion destroys posterior cortex & pedicle


    • T1/T2 hypointense with variable enhancement depending on degree of sclerosis


  • Lymphoma



    • Lytic, permeative bone destruction may cross disc spaces


    • T1 hypointense, T2 iso-/hyperintense, & diffuse uniform enhancement


    • ± Soft tissue mass


  • Multiple Myeloma



    • Multifocal lytic lesions with cortical disruption & extraosseous soft tissue component



      • Pedicle involvement is late


    • Compression fractures with variable canal narrowing



      • 67% appear benign


  • Osteomyelitis, Pyogenic



    • Ill-defined T1 hypointensity in vertebral marrow with loss of adjacent endplate delineation


    • T2/STIR hyperintense marrow


    • Endplate osteolytic/osteosclerotic changes on CT & vertebral collapse


    • Disc space narrowing & enhancement


    • ± Paraspinal/epidural infiltrative soft tissue with loculated fluid (75%)


  • Osteomyelitis, Granulomatous



    • Tuberculous spondylitis shows vertebral collapse & large paraspinal abscess (± calcification)



      • ± Destruction of disc


      • Isolated posterior element involvement


    • Brucellar spondylitis shows anterosuperior epiphysitis (L4) with associated sacroiliitis



      • Intervertebral disc destruction & relatively intact vertebrae


    • Multiple (non)contiguous vertebrae with endplate irregularity & osteolysis


    • Enhancement of epidural soft tissue mass, marrow, disc, dura, subligamentous soft tissues


    • Chronically shows fusion across disc space


Helpful Clues for Less Common Diagnoses



  • Degenerative Endplate Changes



    • Loss of disc space height, loss of horizontal nuclear cleft on T2WI, linear disc enhancement



      • No bone destruction


      • Vacuum phenomenon (low T1/T2 signal)


    • Type 1: T1 hypo-/T2 hyperintense, may show prominent enhancement



      • Inflammatory in orgin, but association with lower back pain controversial


      • Associate with segmental instability with good clinical outcome following fusion


    • Type 2: T1/T2 hyperintense


    • Type 3: T1/T2 hypointense, sclerosis on CT & radiographs


  • Accelerated Degeneration



    • Degenerative changes of disc space/facets at levels adjacent to surgical fusion & congenital segmentation anomalies



      • Most common finding at adjacent segment is disc degeneration


      • No bone destruction


    • Response to altered biomechanical stresses




      • ↑ Intradiscal pressure, ↑ facet loading, & ↑ mobility occur after fusion implicated in causing adjacent segment disease


      • Rate of symptomatic adjacent segment disease ↑ with transpedicular instrumentation (12.2-18.5%)


      • Fusion with other forms of instrumentation or with no instrumentation (5.2-5.6%)


      • Risk factors: Instrumentation, fusion length, sagittal malalignment, facet injury, age, & pre-existing degenerative changes


  • Schmorl Node



    • Focal invagination of vertebral endplate by disc material



      • Low T1/high T2 signal in adjacent marrow if acute


      • Diffuse marrow enhancement if acute, marginal enhancement if subacute


      • Most commonly seen at the T8 through L1 levels & always contiguous with parent disc


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Bony Lesion, Aggressive

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