Osteosarcomas of the skull. Clinical remarks on 19 cases.

BACKGROUND: Osteosarcomas are typically long bone tumors and rarely affect the skull, with most articles reporting single cases. As elsewhere in the body, these lesions may be classified as primary or secondary, chiefly post-Paget and post-radiation therapy.
METHODS: The authors reviewed the osteosarcomas of the skull diagnosed at the Division of Neurosurgery of "La Sapienza" University of Rome. The patients were placed into two groups, according to the treatment received (prechemotherapeutic era and chemotherapeutic era). In the last five patients, a diagnostic-therapeutic protocol was adopted.
RESULTS: The most effective investigations are plain radiographs, computed tomography (CT) with bone windows, and magnetic resonance imaging (MRI), with the latter two allowing assessment of the extraosseous extent of the disease. Chemotherapy has changed the prognosis dramatically, achieving cure in some cases (especially in de novo osteosarcomas). Before the age of chemotherapy, the median survival length was 16 months, but since its introduction, five of nine patients in this study are alive 2 years after diagnosis. The onset of metastases, chiefly to the lung, does not necessarily imply a poor prognosis. The authors propose a schedule for the diagnosis and treatment of new cases of osteosarcoma of the skull.
CONCLUSIONS: Plain radiographs, CT targeted on the bone, and MRI are the most important diagnostic tools. Aggressive chemotherapy together with surgery (eventually including local radiation therapy in nontotal macroscopic surgical removal of the lesions) can drastically modify the prognosis of de novo and post-radiation therapy osteosarcomas.