GCT of Tendon Sheath-MRI

35 year old lady with painful gradually increasing swelling of the index finger in middle phalangeal region of long duration with no history of trauma, with cytology suggesting GCT, shows on MRI, a well defined, lobulated intermediate to low signal intensity SOL in relation to the middle phalanx with no MR demonstrable calcification or intra-articular involvement.

Teaching points Dr MGK Murthy:

-      Second most common tumor of the hand after simple ganglion cysts. 30 – 50 years is the peak incidence. Female to male ratio is 3 : 2.

-      Associated with degenerative joint disease particularly the distal interphalangeal joint.

-      Pathogenesis theories include trauma, disturbed lipid metabolism, osteoclastic proliferation, infection , vascular disturbances,  immune mechanisms , inflammation, neoplasia and metabolic disturbance. Most accepted is reactive or regenerative hyperplasia associated with inflammatory process.

-      Typically occur along the volar aspect of the hand and fingers, most commonly adjacent to the DIP joint (index and long fingers most common) (right more than left).

-      X-ray shows circumscribed soft tissue shadow with cortical erosion in 10 – 20% with  differentials including calcific tendinitis, periosteal chondroma or synovial chondromatosis. MRI shows lobulated, enhancing SOL with scattered low signal foci on all sequences (hemosiderin, like PVNS, though much less).