[Histological aspects of the sarcomatous degeneration of bone in Paget's disease]

After a critical review of the literature and an enquiry based on 70 cases, the author confirms that osteogenic sarcomas and fibrosarcomas constitute the usual means of sarcomatous degeneration in bones affected by Paget's disease. Giant-cell tumours present a distinct group. The problems posed by the initial stages of the malignant transformation and the osteosarcomas with multiple centres are then discussed.