Multiple Giant Cell Tumors of the Tendon Sheath : Separate Volar and Dorsal Lesions Involving Three Digits of the Same Hand Following Repetitive Trauma.

Giant-cell tumors of the tendon sheath correspond to a localized form of pigmented villonodular synovitis. GCTTS typically occur in the hand where they represent the second most common type of soft tissue tumors after synovial ganglions. The etiology of giant cell tumors of the tendon sheath is unknown. Pathogenetic theories have included inflammatory process, trauma, immune mechanisms, neoplasia. Giant cell tumors usually present as a solitary and firm slow-growing nodular lesion, which affects the volar aspect of the hand. Multifocal lesions are rarely described in the literature and commonly involve the same finger or the volar aspect of different fingers. We report a rare case of three separate GCT occurring on both aspects of the hand thus raising the question of their etiology.