Fibroma of the tendon sheath

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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