[Malignant lymphoma presented as left trigeminal neuralgia].

A male, 60 years of age, presented with transient left facial pain located within all three divisions of the trigeminal nerve. Magnetic resonance imaging (MRI) revealed a swollen left trigeminal nerve with gadolinium enhancement. Following schwannoma diagnosis, the patient received Gamma Knife radiosurgery, which proved effective against symptoms of neuralgia and enhanced lesions. A relapse of unsteadiness was noted 11 months after initial treatment. Furthermore, while MRI presented a normal trigeminal nerve, multiple enhanced white matter mass lesions around the lateral ventricles were observed. Lastly, pathological examinations revealed diffuse large B cell lymphomas. The administration of high-dose methotrexate followed with whole brain radiation therapy appeared to have remarkable effects. No recurrences were observed in a 30 month duration following secondary treatment. Malignant lymphoma may present as trigeminal neuralgia. The conclusions from our case report and another literature review follow a difficult to near impossible task of establishing a correct diagnosis without biopsy in the initial stages of trigeminal nerve tumors. Therefore, a careful MRI follow-up is necessary even if the tumors show a favorable response towards primary steroid treatment or Gamma Knife radiosurgery.