BACKGROUND The authors report a case of extra-axial cerebral cavernoma localized at the level of the cavernous sinus. This pathology is extremely rare, therefore, differential diagnosis with tumors such as meningioma is often difficult. During recent years, surgical indications for these lesions, congenital and rarely hereditary, have become more definite due to the considerable progress made in neuroradiologic and microsurgic techniques as well as better anatomic knowledge of this region. METHODS This 49-year-old man was admitted with a 1-year history of diplopia. Cranial computed tomography (CT) scan with contrast medium, performed prior to admission, showed an expansive lesion at the level of the right cavernous sinus. Preoperative neuroradiologic diagnosis, after cerebral magnetic resonance imaging (MRI) with gadolinium enhancement and cerebral panangiography, was probable cavernoma. The lesion was totally removed via a fronto-orbito-temporo-zygomatic craniotomy. RESULTS Postoperatively, the patient had a right oculomotor nerve palsy. This spontaneously resolved 8 months after surgery; diplopia also completely disappeared. Early postoperative control MRI scans with gadolinium on the 2nd postoperative day and 3 months after operation confirmed total removal of the lesion. CONCLUSIONS The clinical onset and neuroradiologic aspect of these lesions and the fact that they rarely involve the cavernous sinus, may sometimes make preoperative diagnosis of cavernous sinus cavernoma difficult. Nevertheless, given the routine use of microsurgical techniques and improved anatomic knowledge of this delicate region, the treatment of choice is surgery. However, when doubts exist regarding achievement of total removal, radiosurgery is still a valid therapeutic tool. (C) 1997 by Elsevier Science Inc.