Neuroradiologic features of primary falx osteosarcoma.

A 56-year-old male high-school teacher developed a personality change over a 2-month period and became unable to keep his attention on his work. He was admitted to Brigham and Women 's Hospital in April 1984 after becoming severely disoriented. Physical examination on admission revealed that the patient was alert and cooperative, but inattentive and indecisive, suggesting frontal lobe dysfunction. Motor function appeared intact. Cranial CT scans without and with intravenous administration of contrast medium (Figs. 1 A and 1 B) showed a large, partially calcified mass along the falx; dense and slightly inhomogeneous contrast enhancement with irregular margins in the bifrontal region was associated with marked surrounding brain edema. Both the CT scan (Fig. 1 C) and skull radiographs showed the skull to be intact. A linear calcification was found underneath the inner table of the frontal bone on the lateral plain skull radiograph . Chest radiography and laboratory examinations were normal , and no other skeletal abnormality was found. Bilateral internal and external carotid angiograms showed the tumor to have feeders bilaterally from both external (middle meningeal artery branches) and internal carotid arteries. Tumor vessels were seen at the arterial phase, a moderate degree of tumor blush appeared at the arterial phase and persisted through the capillary phase, and the anterior superior sagittal sinus was occluded (Fig. 10). No early venous drainage was seen, and no homogeneous tumor stains were found . The preoperative diagnosis was falx meningioma. Bifrontal craniotomy was performed. The falx tumor was removed together with portions of fal x, the anterior one-half of the superior sagittal sinus, and a portion of calvarium. The tumor was approximately 13 x 9 x 2 cm, and consisted of a firm , multinodular, gritty mass that was adherent to resected dura and calvarium. The microscopic appearance was heterogeneous (Fig. 2). A majority of the tumor was composed of a poorly cellular, densely hyalinized matrix. Other areas were hypercellular, populated by pleomorphic , malignant