Tendon sheath fibroma
Tendon sheath fibromas is a rare proliferative mass, with common imaging features of tenosynovial giant cell tumors.
Epidemiology
There is a 3:1 male predominance and arise between the 2nd to 5th decades .
Pathology
Tendon sheath fibromas are lobulated, round-to-oval, encapsulated masses consisting of spindle cells and collagen fibers that arise from the synovium of a tendon sheath .
Location
Tendon sheath fibromas can arise around :
- small joints
- finger (~50%)
- hand (~25%): most commonly the flexor surface
- wrist (~10%)
- large joints (~5%): knee, shoulder, elbow and ankle
They can be intra-articular or extra-articular .
Radiographic features
MRI
- T1: low-to-iso signal
- T2: heterogeneous
- GRE: absent susceptibility artifact
- T1C+: no or variable contrast enhancement
Treatment and prognosis
Treatment is usually surgical excision. There is a very low recurrence rate, and these tumors are not reported to have undergone malignant transformation .
Differential diagnosis
- tenosynovial giant cell tumor: will often show susceptibility artifact on GRE
- nodular fasciitis