脳悪性リンパ腫と認知症

Malignant Lymphoma of the Brain, and Dementia

急性・亜急性の進行性認知機能障害を呈する患者では，悪性リンパ腫を鑑別に挙げる必要がある。本稿では，主に，中枢神経系原発リンパ腫，血管内リンパ腫症，全身性リンパ腫の中枢神経浸潤・再発について概説した。悪性リンパ腫の治療としては，化学療法，化学療法とリツキシマブ併用療法，放射線治療があり，悪性リンパ腫の種類によって治療法が多少異なるものの有効な治療効果を示すので，早期発見・早期治療が重要である。

Abstract

A differential diagnosis of acute and subacute progressive dementias includes malignant lymphoma of the brain. We reviewed primary central nervous system lymphoma (PCNSL), intravascular lymphomatosis (IVL), lymphomatosis cerebri, and the relapse and invasion of systemic lymphomas. PCNSL is confined to the central nervous system; the infiltration and compression by the lymphoma result in adverse neurological symptoms. IVL is a rare form of malignant lymphoma that is characterized by the proliferation of primarily B-cell type lymphoma cells within the blood vessels of various organs. This causes ischemia and results in the associated neurological symptoms. Medical history and neuroimaging studies provide crucial informations to distinguish the lymphomas from other diseases that cause dementia, such an Alzheimer's disease. MRI imaging of the brain using contrast agent, and the biopsy of diseased tissues are essential for the diagnosis of the lymphomas. A histopathological examination is the most effective way to diagnose malignant lymphomas of the brain. Presently, the treatment of choice for PCNSL is the intravenous administration of high dose methotrexate with and without radiation therapy. Futhermore, Rituximab-containing chemotherapy has proved to greatly improve the prognosis of IVL. A better outcome can be achieved with the earlier diagnosis and treatment of the malignant lymphoma of the brain.