Age / Sex : 21 / F

Chief complaint: pain on right wrist (duration: 2 years)

Idiopathic synovial chondromatosis

Discussion

Findings:

1) Plain
radiography

Multiple chondroid calcifications is
noted at dorsoradial aspect of carpal bones of right hand and tiny
calcification is also noted at the ventral aspect of the radiocarpal joint.

 Periarticular osteopenia is noted in the
carpal bones, distal radius, distal ulna, and the 1st to 5th metacarpal bases.

2) MRI

Uneven and diffuse enhancing
synovial hypertrophy with joint effusion is noted on the ventral to dorsal
aspects of radial side of right wrist, which are continous through radiocarpal
joint (Ventral < dorsum). It also extends to mid intercarpal joint.

 Multiple foci showing low signal
intensity on T1 and T2 weighted-images are seen in the hypertrophied synovium.

 Multiple cortical erosions are noted in
the scaphoid, lunate, and articular surface of distal radius.

 There is no bone marrow edema in carpal
bones.

No gross abnormality is seen in
visible tendons.

Differential Diagnosis:

•       Idiopathic synovial chondromatosis

•       CPPD (calcium pyrophosphate
dihydrate) crystal deposition disease

•       Gouty arthritis

•       Amyloidosis

Diagnosis:

Idiopathic synovial chondromatosis

Discussion:

1) Clinical
features

- Uncommon benign neoplastic process

- Chondroid metaplasia in the
synovium of a joint with multiple intraarticular chondral bodies

- Self-limited process that may
recur locally (3% - 23%)

- Treatment: surgical resection

- Men in the third to fifth decades
of life

- Knee (m/c), elbow, shoulder, and
ankle

- Symptoms: Pain (85%–100% of cases)

Swelling (42%–58%)

Restriction of range of motion (38%–55%)

2) Imaging
findings

•       Plain radiography

–      Multiple intraarticular
calcifications

•      
Distributed
evenly throughout the joint

•      
Being
innumerable and very similar in shape

•      
Typical
chondroid ring-and-arc pattern

–      Extrinsic erosion of bone

•       CT

–      Optimal imaging modality to both
detect and characterize calcification and bony erosion

•       MRI

–      T1-WI: Homogeneous, intermediate,
intraarticular signal intensity

–      T2-WI: High signal intensity

+ focal areas of low signal
intensity with all pulse sequences

–      synovial thickening, bone erosion

References:

- Murphey
MD, Vidal JA, Fanburg-Smith JC, Gajewski DA. Imaging of Synovial Chondromatosis
with Radiologic-Pathologic Correlation. Radiographics 2007;27(5): 1465
-1488.