[Evolution of myeloplaxic tumors. Apropos of 21 cases]

21 cases of giant cells tumors were observed. Two were malignant primarily. Twelve cases treated by curetage produced 7 recurrences, one being malignant. Seven cases treated by resection produced no recurrence. The authors believe that the prognosis and the indications are based more on clinical and radiological features than on histologic grading studies.