[Benign giant cell tumors associated with Paget's disease. Apropos of 1 case].

The authors report the observation of two benign giant-cell tumours that developed in the cranium of Paget's disease patients. The two tumours were resected and cure was complete. Eighteen other cases of benign giant-cell tumours were found in the literature. All were discovered in relation to tumefaction occurring in an affected bone in a patient with generalized Paget's disease, often unrecognized. The tumours were usually unique although multiple tumours were found, with particular predilection for the bones of the cranium and the face. The radiological signs consisted of an osteolytic zone in an affected bone; there were no specific characteristics and it was not possible to distinguish the tumours from a malignant tumour. Diagnosis was based upon an anatomo-pathological examination. In the 18 cases in the literature, the benign caracter indicated by the biopsy was confirmed by the favourable evolution. In contrast in 17 other cases the atypical nature of the stroma, the irregular arrangement of the giant cells together with the occurrence of atypical mitoses and the abnormal character of the vascularization indicated straight away the malignant nature of the lesions, which was regularly and rapidly fatal.