NCOG-08. A RARE PRIMARY CNS T-CELL LYMPHOMA CASE: 12-YEAR FOLLOW-UP AFTER CHEMOTHERAPY

Abstract INTRODUCTION Primary central nervous system (CNS) T-cell lymphoma (PCNSTL) is a rare hematological malignancy. There is mere literature to guide the treatment. CASE REPORT This study is an update on our previously reported case at SNO in 2012 after a 12-year follow-up, detailing the long-term outcome of our chemotherapy treatment for a case of PCNSTL. In 2011, a 26-year-old immunocompetent patient presented with severe headache, vomiting, and lethargy. The brain MRI found more than a dozen masses on his bilateral cerebral hemispheres. Brain biopsy discovered T-cell lymphoma. The patient was started biweekly high-dose-methotrexate (HD-MTX) in 2011. After three doses, there was no noticeable improvement on his brain MRI. His treatment was switched to HD-MTX plus high dose cytarabine regimen (Ferreri et al, The Lancet, 2009). The patient could not tolerate cytarabine; thus, was changed back to HD-MTX. The patient responded to the rest of HD-MTX well. He completed 8 doses of biweekly HD-MTX induction therapy and 2 doses of monthly HD-MTX maintenance therapy. His brain MRI showed complete resolution of enhancement on one-year follow-up image. The patient has been off-treatment and monitored under surveillance of brain MRIs since 2012. He has had no lymphoma recurrence over the past 12 years. His physical functions have been preserved with a Karnofsky Performance Status scale of 80%. Neuropsychological evaluations in 2015, 2018, and 2023 showed mild cognitive impairment with gradual improvements in his working memory and semantic fluency. His Mini-Mental Status Exam scores have remained stable to mild improvement, recording 27/30 in 2015, 26/30 in 2018, 27/30 in 2023 and 28/30 in 2024. DISCUSSION The patient, who is now 38 years old, has surpassed a 12-year survival mark. Our experience emphasizes the feasibility of treating PCNSTL through chemotherapy only, which might be potentially beneficial in surviving and preserving major aspects of brain function.