NONEPIPHYSEAL GIANT-CELL TUMOR OF THE LONG BONES - CLINICAL, RADIOLOGIC, AND PATHOLOGICAL-STUDY

Background. Giant cell tumors (GCT) usually involve the epiphyses of l ong bones and only rarely involve the metaphysis or diaphysis without epiphyseal extension. Methods. This report presents the clinical and p athologic features of 14 patients with metaphyseal and diaphyseal GCT. Of these tumors, 10 were metaphyseal; 2, metadiaphyseal; and 2, diaph yseal. Results. The sites of involvement included the proximal tibia i n six patients, distal radius in three, proximal fibula in one, distal fibula in one, distal ulna in one, proximal humerus in one, and dista l femur in one. Radiographically, the tumors were lucent, and the majo rity were sharply marginated without sclerosis. By contrast with conve ntional epiphyseal GCT, which generally appear in the mature skeleton, a large proportion (50%) of the GCT in this series were in patients w ho had open epiphyseal growth plates. Despite the unusual clinical pre sentation, the behavior of metaphyseal and diaphyseal GCT was similar to that of the typical epiphyseal GCT. There was a 43% recurrence rate after curettage in this series. Conclusions. It is important to disti nguish this subset of GCT from other giant cell-rich lesions more comm on in these sites, including aneurysmal bone cyst, osteosarcoma, and n onossifying fibroma.