Pagetic sarcoma of the calvarium: report of two cases

Two cases of calvarium sarcoma with intracranial extension, consecutive to Paget disease of the skull are presented. The neurosurgical implications of this rare complication of a common disease are reviewed. In both cases, th e symptoms of malignant degeneration were unspecific and blurred by the pre sence of a well-known Paget disease. Increasing headaches, focal neurologic al deficits and signs of intracranial hypertension were observed. Skull X-r ays and Computerised Tomography did not allow to make the difference betwee n Pagetic bone and sarcoma. In the second case, Magnetic Resonance Imaging was the most accurate in determining the precise localisation of the tumour , and the subdural invasion. Extensive surgical resection was carried out, by craniectomy of the tumoural bone, followed by cranioplasty. Dural sinus involvement and tumour hypervascularisation caused important peroperative b lood loss in both patients. In the second case the tumour invaded the subdu ral space through a Pacchioni granulation. Survival of patients with Pageti c sarcoma seems shorter when compared to post-radiation or primitive osteos arcoma, despite adjuvant therapies, probably because of late diagnosis and incomplete surgical resection. The mean reported survival rate is 6 months. Although the first patient died within 4 months, in the second case, the a uthors obtained a more than two year survival with aggressive surgery alone . These cases also illustrate the polymorphism of sarcomatous degeneration of Pagetic calvarium, the interest of MRI, and the need for close surveilla nce of patients with known Pagets disease of the skull.