ATYPICAL CENTRAL-NERVOUS-SYSTEM LYMPHOMA AT THE CRANIAL BASE - REPORTOF 4 CASES

OBJECTIVE AND IMPORTANCE: Primary central nervous system lymphoma is a disease with increasing incidence. Atypical presentations are becomin g more frequent.CLINICAL PRESENTATION: Three patients bearing cavernou s sinus lesions presented initially with periorbital pain and diplopia . Tolosa-Hunt syndrome was the initial presumptive diagnosis for two p atients, and meningioma was the diagnosis for the third patient. A fou rth patient presented with left ear pain, and a mass in the left inter nal auditory canal was thought to represent an acoustic neuroma. INTER VENTION: For all four patients, an operative pathological diagnosis wa s obtained and was compatible with central nervous system lymphoma. Al l patients were treated with osmotic blood-brain barrier disruption wi th intra-arterial chemotherapy using a methotrexate-based regimen. CON CLUSION: AII four cases included atypical presentations of lymphoma. T hese cases again illustrate that a correct diagnosis cannot be obtaine d based only on imaging and clinical findings.