2014 Volume 17 Issue 2 Pages 97-109
Primary central nervous system lymphoma (PCNSL) is an uncommon subtype of non-Hodgkin lymphoma, the lesions of which are confined to the CNS without evidence of systemic disease. The vast majority of PCNSL show the diffuse large B-cell lymphoma histopathology. Patients with PCNSL present with focal neurological deficits, neuropsychiatric symptoms, signs of raised intracranial pressure, and seizures. Periventricular lesions are most common, and the lesions appear isointense to hypointense on T1-weighted MRI images and isointense to hyperintense with respect to cortex on T2-weighted MRI images, and show marked enhancement after contrast medium administration. PCNSL is primarily treated with high-dose methotrexate (HD-MTX)-containing chemotherapy, followed by whole-brain radiation therapy (WBRT) of 40 to 45 Gy, leading to complete response rates of 30% to 87% and 5-year overall survival rates of 22% to 70%. However, delayed neurocognitive decline accounting for the combined effects of HD-MTX and WBRT can occur, especially in elderly patients. We encountered a total of 10 patients with PCNSL during the last 3 years. The treatment included HD-MTX-containing intensive chemotherapy, intraventricular administration of cytotoxic drugs through Ommaya reservoir in place, high-dose chemotherapy with autologous hematopoietic stem cell support, and WBRT; however, only one patient showed disease-free survival of over 2 years. On the other hand, systemic malignant lymphoma can involve the nervous system at any level. The most common site of CNS relapse is the meninges, and patients typically present with cranial nerve deficits. For patients with CNS relapse, systemic HD-MTX is suggested as for those with PCNSL; however, survival has been poor, with a median of 2 to 5 months. Thus, administration of CNS prophylaxis should be incorporated into the initial treatment of patients at high risk of CNS relapse.
