Possible soft tissue chondroma-Differential Diagnosis.

Adult with pain and swelling of long duration  with no history of trauma.  Professor-Resident series-by Dr MGK Murthy.

How do you describe it?

A relatively well defined, juxta articular, soft tissue , calcified lesion  with area of peripheral rim or curvilinear pattern with no intra articular extension and no bony response including sclerosis or periosteal reaction or destruction

Possibilities?

Likely to represent benign soft tissue calcifying lesions of juxt articular locations of extremity, Soft tissue chondroma is possible

Teaching Points :

·        80% occur in fingers with hands and feet being very common

·        common in 30-60 yrs age group

·        some suggest synovial origin and hence is always juxtaarticular , others argue it is extraartiular  and represent  developmental faults or metaplasia

·        HPE could vary from immature chondroblasts to mature chondrocytes with fibrohyaline matrix

·        Calcification is peripheral rim or curvilinear shaped with no periosteal response or joint involvement

What are the other possibilities ?

1.     synovial osteochondromatosis- should extend intraartiuclar with multiple well defined shapes

2.     crystal deposition disease - biochemistry with pain of acute nature with amorphous and nodular calcifications

3.     Tumoral calcinosis – shows fluid levels and is large

4.     Myositis ossificans- uncommon at this site and shows periosteal response

5.     PSS, Raynauds phenomenon, SLE etc-  history and well defined nature along with multiplicity

6.     Malignant etiologies like synovial sarcoma – bone destruction/osteoporosis, short duration along with spotty calcification

7.     Chondrosarcoma- aggression , large and irregular calcification

What is the further workup?

CE MRI along with F18 Bone scan would delineate  bony, soft tissue anatomy and activity of the lesion to narrow down the differentials