10223-ML-12 SYSTEMIC RELAPSE OF PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA

Abstract PCNSL remains a poor prognosis, with many patients relapsing despite induction high-dose MTX-based chemotherapy and subsequent maintenance therapy. Most recurrences occur in the brain parenchyma, but in rare cases, systemic relapse may occur. We report the clinical and pathological features of the patients with systemic relapse of PCNSL. We examined 165 PCNSLs treated at our hospital since 2005. 102 of the 165 had recurrence, and 11 of these were diagnosed as systemic relapse. The 11 patients at the time of initial diagnosis had 8 males and 3 females, age 49-81 years (median 67), and KPS 50-90 (median 70). The 11 patients at the time of recurrence had age 62-66 years (median 71), KPS 50-100 (median 60), and the sites of recurrence were abdominal lymph nodes in 3 patients, gastrointestinal tract in 3, pleural effusion in 3, and others in 2. The time to systemic relapse ranged from 11.3 to 156.1 months (median 36.4), survival after recurrence ranged from 0.1 to 89 months (median 16.1), and overall survival ranged from 16.5 to 192 months (median 66.5). Tissue sampling at relapse was performed in 9 patients, 8 of whom had DLBCL. Recurrence of PCNSL is often in the brain, and although recurrence outside the CNS occurs in less than 10%, careful follow-up is necessary. Although it has been reported that recurrence in the testes and breast is common, in our case, recurrence in lymph nodes and pleural effusions was common, and genetic histological evaluation, including discussion of the difference from the primary CNS, is considered necessary. Although the prognosis and KPS of PCNSL are poor, there are cases in which a good condition can be maintained with reliable diagnosis and treatment. Detailed clinical information, including genetic analysis at the time of initial onset and at the time of recurrence, is needed.