Giant cell tumor of tendon sheath simulating giant cell tumor of bone: report of a case.

A 24-year-old male patient presented with a painful eccentric lytic lesion of the proximal tibial epiphysis with a soft tissue component. Clinical and radiological assessment led to the tentative diagnosis of aggressive giant cell tumor of bone. The patient was treated with curettage, high-speed burr, and cementation after intraoperative pathology consultation. The final pathological report indicated that the tumor was giant cell tumor of the tendon sheath with bone invasion. Although uncommon, GCTTS should be considered in the differential diagnosis of such lesions when there is a prominent soft tissue component. Although the resection was intralesional, the thermal effect of the cementation of the involved cavity and complete removal of the tendon sheath may allow successful local control conjecture of lesions that otherwise present with clinical and radiographic findings suggesting giant cell tumor of the bone.