All seventy-five cases recorded as giant-cell tumor of bone in the
Swedish Cancer Registry for the years 1958 through 1968 were analyzed. At
reexamination, fifty-three cases constituted genuine giant-cell tumor of
bone and twenty cases were so-called "giant-cell variants". The genuine
giant-cell tumors showed a significantly higher incidence in the urban than
in the rural population. The recurrence rate was 42 per cent. Patients
under the age of twenty-five rarely had recurrences. A high recurrence rate
was found among patients with tumors located in the distal end of the femur
and the proximal end of the tibia. Tumors penetrating through the bone
cortex were more aggressive than those located entirely within bone,
regardless of tumor size and presence or absence of spontaneous fracture. A
malignant course was found in 11.3 per cent of cases, predominantly in
patients with tumors in the femur. Histopathological grading was of no
prognostic value. Primary en bloc resection with or without prosthetic
replacement is recommended in patients over the age of twenty-five.