Case report and review of the literature of primary central nervous system lymphoma of the fourth ventricle.

Primary central nervous system lymphoma of the fourth ventricle is very rare. We present a case of primary central nervous system lymphoma originating from the fourth ventricle and review cases reported in the literature. A 54-year-old man with no previous medical history presented with headache and nausea. Magnetic resonance imaging showed a homogeneously enhancing tumor in the fourth ventricle and obstructive hydrocephalus. We performed biopsy of the tumor, which was diagnosed pathologically as diffuse large B-cell lymphoma. Although the tumor disappeared after 5 cycles of R-MPV regimen, the patient required repeated ventricular drainage and finally received a ventriculoperitoneal shunt. Complete response was achieved after 2 cycles of high-dose cytarabine chemotherapy with an autologous peripheral blood stem cell transplant. There was no sign of recurrence at 20 months after biopsy. Morbidity arising due to radical resection/radiotherapy of resistant primary central nervous system lymphoma originating from the fourth ventricle could be prevented by ventriculoperitoneal shunting with chemotherapy and autologous blood stem cell transplantation.