Characteristics of Central Nervous System (CNS) Involvement in Children With Non-Hodgkin's Lymphoma (NHL) and the Diagnostic Value of CSF Flow Cytometry in CNS Positive Disease.

OBJECTIVE: To investigate the characteristics of central nervous system (CNS) involvement in children with non-Hodgkin's lymphoma (NHL) and the value of flow cytometry (FC) in the diagnosis of CNS disease in pediatric NHL. METHODS: The data of 56 newly diagnosed pediatric NHL patients with CNS involvement (CNS+/mass, CNS+/palsy, CNS+/CSF) were analyzed. The proportions and formats of CNS disease in different pathological types were compared. In addition, FC and conventional cytology (CC) of cerebrospinal fluid (CSF) were carried out in 383 newly diagnosed NHL cases. RESULTS: A total of 383 children with NHL were enrolled. Among these patients, 56 (14.6%) were diagnosed with positive CNS involvement (CNS+), 33 had bulky disease (tumor diameter >10 cm), 32 had bone marrow invasion, 32 had lactate dehydrogenase levels >1000 U/L, and 25 had invasion of more than 4 organs at the time of diagnosis. There were 14 patients with T lymphoblastic lymphoma (T-LBL), 9 with B lymphoblastic lymphoma (B-LBL), 26 with Burkitt's lymphoma (BL), and 2 with Epstein-Barr virus-positive diffuse large B cell lymphoma (EBV + DLBCL). Among the 56 CNS+ patients, 35 were CSF-positive (CSF+); there were 2 patients who were CSF+ via CC detection and 35 who were CSF+ via FC detection. The difference between CC and FC was statistically significant (P < 0.01). In the T-LBL group, 14 patients were CNS+/CSF, and in the B-LBL group, 8 were CNS+/mass. In the BL group, 22 patients were CNS+/mass and 15 were CNS+/CSF. In the anaplastic large-cell lymphoma group, 5 patients were CNS+/mass. Nine of the 56 CNS+ patients had events. The 2-year overall survival rate was 87% ± 0.046%, and the 2-year event-free survival rate was 76.2% ± 0.07%. CONCLUSION: CNS+ diagnoses were more common in pediatric NHL patients with bulky disease and/or bone marrow involvement and/or involvement of more than 4 organs at the time of diagnosis, and they were also common in the EBV + DLBCL and BL groups. FC of CSF showed important clinical significance in the diagnosis of CNS disease in pediatric NHL patients, and it can be used to significantly improve the CNS+ detection rate.

Prognostic factors for CNS control in children with acute lymphoblastic leukemia treated without cranial irradiation.

To identify the prognostic factors that are useful to improve central nervous system (CNS) control in children with acute lymphoblastic leukemia (ALL), we analyzed the outcome of 7640 consecutive patients treated on Chinese Children's Cancer Group ALL-2015 protocol between 2015 and 2019. This protocol featured prephase dexamethasone treatment before conventional remission induction and subsequent risk-directed therapy, including 16 to 22 triple intrathecal treatments, without prophylactic cranial irradiation. The 5-year event-free survival was 80.3% (95% confidence interval [CI], 78.9-81.7), and overall survival 91.1% (95% CI, 90.1-92.1). The cumulative risk of isolated CNS relapse was 1.9% (95% CI, 1.5-2.3), and any CNS relapse 2.7% (95% CI, 2.2-3.2). The isolated CNS relapse rate was significantly lower in patients with B-cell ALL (B-ALL) than in those with T-cell ALL (T-ALL) (1.6%; 95% CI, 1.2-2.0 vs 4.6%; 95% CI, 2.9-6.3; P < .001). Independent risk factors for isolated CNS relapse included male sex (hazard ratio [HR], 1.8; 95% CI, 1.1-3.0; P = .03), the presence of BCR-ABL1 fusion (HR, 3.8; 95% CI, 2.0-7.3; P < .001) in B-ALL, and presenting leukocyte count ≥50×109/L (HR, 4.3; 95% CI, 1.5-12.2; P = .007) in T-ALL. Significantly lower isolated CNS relapse was associated with the use of total intravenous anesthesia during intrathecal therapy (HR, 0.2; 95% CI, 0.04-0.7; P = .02) and flow cytometry examination of diagnostic cerebrospinal fluid (CSF) (HR, 0.2; 95% CI, 0.06-0.6; P = .006) among patients with B-ALL. Prephase dexamethasone treatment, delayed intrathecal therapy, use of total intravenous anesthesia during intrathecal therapy, and flow cytometry examination of diagnostic CSF may improve CNS control in childhood ALL. This trial was registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-14005706).

Detection of occult cerebrospinal fluid involvement during maintenance therapy identifies a group of children with acute lymphoblastic leukemia at high risk for relapse.

We aimed at assessing the clinical significance of the levels of acute lymphoblastic leukemia (ALL) cells in samples of cerebrospinal fluid (CSF) during therapy. We studied 990 CSF samples from 108 patients, at the time of diagnosis (108) and at each time of intrathecal therapy (882). The proportions of leukemic cells in CSF samples were assessed by flow cytometry (FCM). Patients with central nervous system (CNS) involvement at diagnosis (FCM+) showed predominantly a T-ALL, and higher percentages of known negative prognostic factors: high risk group, higher white blood cell counts, normal karyotype, and the BCR-ABL fusion gene. No differences in relapse free survival (RFS) and overall survival (OS) were observed between FCM+ versus FCM- at diagnosis. Patients with CNS involvement during therapy showed significantly older age, and higher frequencies of T-cell leukemia. We found a significantly higher RFS in patients with FCM+ during therapy. The detection of subclinical CNS disease by FCM during maintenance was associated with significantly lower 3-years RFS and 3-years OS. A sensitive methodology like FCM can be applied for a close follow-up of the levels of ALL in CFS samples, and may identify a group of patients at high risk for relapse.

T cell acute lymphoblastic leukaemia presenting with sudden onset right oculomotor nerve palsy with normal neuroradiography and cerebrospinal fluid studies.

Leptomeningeal disease presenting with neurological dysfunction is not uncommon in leukaemia. However, it is often accompanied by abnormalities in cerebrospinal fluid (CSF) studies and/or neuroradiography. Here, the authors describe a case of a young patient presenting with sudden onset right oculomotor nerve palsy with normal neuroradiography and CSF studies, who was subsequently diagnosed to have T cell acute lymphoblastic leukaemia (T-ALL). This case highlights that neurological manifestations can be the initial presenting feature of T-ALL and can occur suddenly despite normal neuroradiography and initial CSF studies.