Primary central nervous system T-cell lymphoma: An analysis from the surveillance, epidemiology, and end results program.

BACKGROUND: Primary central nervous system T-cell lymphoma (PCNSTCL) is a rare neoplasm with few data regarding its common features and survival characteristics. OBJECTIVE: To explore the Surveillance, Epidemiology, and End Results 18 (SEER 18) database to determine the epidemiology of PCNSTCL. METHODS: The SEER 18 registry database was queried to identify patients diagnosed with PCNSTCL from 1973 to 2014 and extract their information. Age-specific rates and Kaplan-Meier overall survival (OS) were calculated. A Cox proportional hazards model was applied to investigate relationships between various demographic/treatment variables and OS. RESULTS: The age-specific incidence rates were higher in the older population (≥60 years). Among 59 PCNSTCL cases from the SEER 18, the mean age at presentation was 55.8 years (SD, ±17.95), with a male predominance (1.36:1.00). The median follow-up was 8 months, and the median OS was 8 months (SE, ±4.162). The 1-, 3-, and 5-year OS was 46.3% [95% CI, 33.4%-59.2%], 32.8% [20.3%-45.3%], and 32.8% [20.3%-45.3%], respectively. Seventeen of the 59 patients survived at last follow-up. Patients < 60 years had a greater 3-year OS compared with patients ≥ 60 years (52.6% [33.6%-71.6%] vs 13.9% [1.4%-26.4%]. Multivariate analysis has demonstrated that only age at diagnosis (≥60/<60 years) exhibited a significant relationship with OS (HR, 3.495 [1.688-7.235];p = 0.001). Sex (female/male) was observed to have a doubted trend towards significance (HR, 0.487 [0.231-1.030]; p = 0.060). CONCLUSIONS: PCNSTCL is generally of poor prognosis but younger age at diagnosis (<60 years) predicts a better prognosis.

Primary Central Nervous System T-Cell Lymphoma With Aberrant Expression of CD20 and CD79a: A Diagnostic Pitfall.

Primary central nervous system T-cell lymphoma (PCNSTCL) is rare, accounting for 2% of CNS lymphomas. We report the first case of PCNSTCL with aberrant expression of CD20 and CD79a in an 81-year-old man with a left periventricular brain mass. A biopsy revealed dense lymphoid infiltrate consisting of medium-sized cells in a background of gliosis and many histiocytes. The lymphoid cells were positive for CD2, CD3, CD7, CD8, T-cell intracellular antigen-1, granzyme B, CD20, and CD79a and negative for CD4, CD5, PAX-5, OCT-2, BOB-1, human herpes virus-8, and Epstein-Barr virus-encoded small RNAs. Molecular studies revealed clonal TCR-ß and TCR-γ gene rearrangements and negative immunoglobulin gene rearrangements. The patient was treated with chemotherapy (vincristine and methotrexate) and rituximab, but he died 1 month after the diagnosis. This is a unique case that emphasizes the use of a multimodal approach, including a broad immunohistochemical panel and molecular studies in lineage determination for lymphomas with ambiguous phenotype.