HTLV─Ⅰ関連中枢神経系原発悪性T細胞性リンパ腫の1例

A Case of Primary T-Cell Central Nervous System Lymphoma (T-PCNSL) Relevant to HTLV-Ⅰ

Ⅰ．はじめに

　中枢神経系原発悪性リンパ腫（primary central nervous system lymphoma：PCNSL）は，診断時に神経系以外には明らかなリンパ腫のみられない，中枢神経系に発生する節外性悪性リンパ腫と定義される³⁾．

　わが国では節外性リンパ腫の1～2％がPCNSLで，そのうちT細胞性起源のもの（T-PCNSL）は8.5％に過ぎない⁷⁾．これまでの報告では，大量methotrexate（MTX）療法や手術・放射線療法などが施行されているが，その希少性もあり標準的治療法は未だ確立されていない^4,9,12,13)．今回，われわれは急速に症状が進行し不慮の転帰をとった，中枢神経系原発の悪性T細胞性リンパ腫の1例を経験した．脳の剖検所見と併せて報告する．

　Primary T-cell lymphoma of the central nervous system lymphoma (T-PCNSL) is an extremely rare tumor. A human T-cell lymphoma virus typeⅠ(HTLV-Ⅰ) associated adult TCL often involves the CNS during its course but disease limited to the CNS is exceptional. We report a case of a 63-year-old male with a highly malignant TCL localized in the bilateral cerebral hemispheres. The patient was HTLV-Ⅰpositive but no systemic disease was detected after various examinations. We discuss the clinico-pathological features of TCL in the CNS reported in the literature including our case and compare them with those of B-cell lymphomas.