Atypical central nervous system lymphoma at the cranial base: report of four cases.

OBJECTIVE AND IMPORTANCE: Primary central nervous system lymphoma is a disease with increasing incidence. Atypical presentations are becoming more frequent. CLINICAL
PRESENTATION: Three patients bearing cavernous sinus lesions presented initially with periorbital pain and diplopia. Tolosa-Hunt syndrome was the initial presumptive diagnosis for two patients, and meningioma was the diagnosis for the third patient. A fourth patient presented with left ear pain, and a mass in the left internal auditory canal was thought to represent an acoustic neuroma. INTERVENTION: For all four patients, an operative pathological diagnosis was obtained and was compatible with central nervous system lymphoma. All patients were treated with osmotic blood-brain barrier disruption with intra-arterial chemotherapy using a methotrexate-based regimen.
CONCLUSION: All four cases included atypical presentations of lymphoma. These cases again illustrate that a correct diagnosis cannot be obtained based only on imaging and clinical findings.