Enlarged Vertebral Body/Posterior Element



Enlarged Vertebral Body/Posterior Element


Lubdha M. Shah, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Facet Arthropathy



    • Facet Arthropathy, Cervical


    • Facet Arthropathy, Lumbar


    • Baastrup Sign


  • Paget Disease


  • Aggressive Hemangioma


  • Compensatory Enlargement



    • Scoliosis


    • Spondylolysis


  • Congenital Fusion


Less Common



  • Metastases, Lytic Osseous


  • Aneurysmal Bone Cyst


  • Osteoblastoma


  • Chordoma


Rare but Important



  • Fibrous Dysplasia


  • Chondrosarcoma


  • Osteochondroma


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Osteoblastoma should always be considered in the differential diagnosis of painful scoliosis


  • Center of the lesion in the vertebral body vs. posterior element may help with the differential diagnosis


Helpful Clues for Common Diagnoses



  • Facet Arthropathy, Cervical



    • Capsular laxity and joint space narrowing may lead to degenerative spondylolisthesis


    • Osteoarthritis of synovial-lined zygapophyseal joints


    • Hypertrophic changes with osteophytes, normal bone mineralization, & joint space narrowing


  • Facet Arthropathy, Lumbar



    • Osseous hypertrophy with articular joint space narrowing and encroachment upon neural foramen


    • Irritation of synovium produces synovial hyperplasia with paradoxical joint space widening


    • Facet arthrosis syndrome with low back, hip, and buttock pain aggravated by rest


  • Baastrup Sign



    • Close approx. & contact of adjacent spinous process with reactive sclerosis, enlargement & flattening of apposing interspinous surfaces


    • “Kissing” spinous processes


    • Cystic degeneration of interspinous ligaments and posterocentral epidural cyst


  • Paget Disease



    • Enlarged vertebra and neural arch with diffusely coarsened & haphazard bony trabecular pattern



      • Most commonly L3 & L4


      • Cortex is thickened


      • Anterior concavity of the vertebral body is lost


    • Can cause spinal stenosis & neural foraminal narrowing


    • No epidural soft tissue component unless sarcomatous degeneration


  • Aggressive Hemangioma



    • Expanded & indistinct cortex, irregular honeycombing pattern, & soft tissue mass



      • Trabecular condensation thinner in comparison to Paget disease


    • Lesions commonly involve entire vertebral body with extension into neural arch


    • Typically occur between T3 & T9


    • Epidural extension may cause cord compression


    • Can become symptomatic with growth, which often occurs during pregnancy


  • Compensatory Enlargement



    • Scoliosis



      • Minimal structural vertebral deformities & advanced degenerative changes


      • Facet osseous overgrowth, asymmetric disc space, & discogenic sclerosis at the concave aspect of the scoliosis


      • Unilateral radicular symptoms on the side of the concavity of the deformity


    • Spondylolysis



      • Defects in pars interarticularis (PI) may be due to repetitive stress injury


      • Spinal canal is elongated at the level of the pars defect on axial imaging


      • Most common at L5


      • Sclerosis of PI, volume averaging of superior facet spur, partial facetectomy, blastic metastases may mimic spondylolysis



  • Congenital Fusion



    • Vertebral bodies smaller than normal with tapered contour at fused disc space


    • Rudimentary disc space with reduced height & diameter, “wasp waist”


    • Degenerative changes at adjacent levels


    • ± Fusion of posterior elements


Helpful Clues for Less Common Diagnoses



  • Metastases, Lytic Osseous



    • 50-70% bone destruction required for detection on radiography


    • Lesion involves posterior cortex & pedicle


    • Diffuse involvement of marrow gives the appearance of brighter disc than bone on T1WI


    • Fat suppression on enhanced T1WI helpful to unmask lesions


  • Aneurysmal Bone Cyst



    • Arise in the neural arch with the majority (75-90%) extending into the vertebral body


    • Expansile remodeling of bone with cortical thinning


    • Fluid-fluid levels with hemorrhage


    • No tumor matrix


  • Osteoblastoma



    • Originate in the neural arch, often extend into the vertebral body


    • > 1.5 cm (osteoid osteoma < 1.5 cm)


    • Narrow zone of transition with sclerotic rim


    • Bone matrix on CT or radiograph


    • May be associated with an aneurysmal bone cyst (10-15%)


    • Painful scoliosis (50-60%)


  • Chordoma



    • Rare involvement of the vertebral body


    • Purely lytic


    • T2 hyperintense with multiple septations


    • Variable enhancement


    • Amorphous intratumoral Ca++ in 30% of vertebral lesions


Helpful Clues for Rare Diagnoses



  • Fibrous Dysplasia



    • Neural arch involvement > vertebral body


    • Spine involvement in polyostotic disease


    • Mildly expansile lesion with characteristic ground-glass matrix


    • Heterogeneous T1 & T2 signal and enhancement


  • Chondrosarcoma



    • Lytic, destructive lesion with cortical destruction and extension into the soft tissues


    • ± Chondroid matrix (50%) of “rings & arcs”


  • Osteochondroma



    • Sessile or pedunculated osseous lesion contiguous with the parent vertebra


    • Cartilaginous cap > 1.5 cm in adults concerning for malignant transformation






Image Gallery









Axial bone CT shows severe left unilateral facet overgrowth image, causing moderately severe central stenosis.

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Enlarged Vertebral Body/Posterior Element

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