Long-term survival of diffuse large B cell lymphoma of the trigeminal region extending to the Meckel's cave treated by CHASER therapy: case report.

A 52-year-old man with a history of malignant lymphoma of the cecum presented with lancinating facial pain in the left. Magnetic resonance imaging (MRI) revealed a tumor in the Meckel's cave extending along the trigeminal nerve. The tumor was partially removed via left retrosigmoid lateral suboccipital craniotomy. Histological examination showed findings consistent with diffuse large B cell lymphoma, which was later confirmed to be metastatic lesion from the cecal lesion. Postoperative chemotherapy with cyclophosphamide, high dose, cytarabine, steroid (dexamethasone), etoposide, and rituximab (CHASER) followed by whole brain irradiation (30 Gy) resulted in complete remission. Although facial pain persisted, the patient's general condition remained favorable and he did not experience recurrence over the 51-month follow-up period. Histological confirmation and awareness of malignant lymphoma are very important to determine the therapeutic strategy and to avoid misdiagnosis or delayed diagnosis. Long-term survival of patients with metastatic malignant lymphoma in the Meckel's cave extending along the trigeminal nerve was very rare. In addition, metastatic malignant lymphoma in the extra-axial and peripheral nervous tissue might be different from primary central nervous system lymphoma in the white matter, since the efficacy of chemotherapeutic agents against malignant lymphomas in the extra-axial regions is not attenuated by the blood brain barrier.