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Age / Sex : 69 / M
Chief complaint : Lower back pain
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Courtesy: Wan Tae Kim, Veterans Health Service Medical Center
Diagnosis: Tophaceous gouty arthritis of lumbar spine
Discussion
Findings:
Noncontrast
axial CT of L4-5 level shows a hyperattenuating soft tissue mass and severe bony
erosions in both laminae and facet joints.
Axial
and sagittal T1-weighted MRI demonstrates heterogeneous intermediate signal
intensity soft tissue mass and erosive change in facet joints.
Axial
and sagittal T2-weighted MRI shows the heterogenous low signal intensity mass
with soft tissue component. There is juxtaarticular bony erosions around facet
joints.
Differential Diagnosis:
1. Rheumatoid arthritis
2. CPPD (Calcium pyrophosphate deposition
disease)
3. PVNS (Pigmented villonodular
synovitis)
Diagnosis:
Tophaceous gouty arthritis of lumbar spine
Discussion:
Gout
is a common inflammatory arthritis that is characterized by the deposition of
monosodium urate crystals in the synovial joints and soft tissues. Gouty
involvement of the axial skeleton is uncommon, and urate deposition in the
spine is rare.
Radiographic
features of spinal gout may include degenerative spondylosis, discovertebral
erosions, bone destruction, spinal deformity, and occasionally pathologic
fractures.
CT
scan is useful to show bony erosions with sclerotic margins inside the joint or
periarticularly. These erosions are usually associated with a surrounding
lobulated hyperintense amss.
MR imaging
features of tophaceous gout in the peripheral joints is characteristic. The
tophi have manifested as homogeneous intermediate to low signal intensity on
T1-weighted images.
The reported
pictures of the tophi on T2-weighted images varied, ranging from homogeneous
high signal intensity to homogeneous low signal intensity. Hyperintense signal
on T2-weighted images reflect high protein content in the amorphous center of
the tophus. The low signal intensity on T2-weighted images may refer to regions
of calcifications, mature fibrous tissue and urate crystals, or hemosiderin
deposits in the tophus.
The clinical
information, laboratory data, and characteristic MR imaging appearance could
aid to properly diagnosis.
The
differential diagnosis has included rheumatoid arthritis, calcium pyrophosphate
dehydrate disease (CPPD), pigmented villonodular synovitis (PVNS), metastatic
disease, facet joint infection a swell as calcified tumor.
The
diagnosis of spinal tophaceous gout should be considered when periarticular
deposits contain very low signal foci on all MR images and internal
calcifications on CT images.
References:
1.
Lu F, Jiang J, Zhang F, Xia X, Wang L, Ma X.
Lumbar spinal stenosis induced by rare chronic tophaceous gout in a 29-year-old
man. Orthopedics. 2012 Oct;35(10):e1571-5.
2.
Marinho F,
Zeitoun-Eiss D, Renoux J, Brasseur JL, Genestie C, Grenier P. Tophaceous gout
of the spine: case report and review of the literature. J Neuroradiol. 2012
May;39(2):123-6.
3.
Hsu CY, Shih TT, Huang KM, Chen PQ, Sheu JJ,
Li YW. Tophaceous gout of the spine: MR imaging features. Clin Radiol. 2002
Oct;57(10):919-25.
4.
Jegapragasan M, Calniquer A, Hwang WD, Nguyen
QT, Child Z. A case of tophaceous gout in the lumbar spine: a review of the
literature and treatment recommendations. Evid Based Spine Care J. 2014
Apr;5(1):52-6.
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