Limbic encephalitis due to GABAB and AMPA receptor antibodies: a case series.

BACKGROUND: Two novel antibodies (abs) directed to γ-aminobutyric acid B receptor (GABA(B)R) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in patients with limbic encephalitis (LE) were first described by the Philadelphia/Barcelona groups and confirmed by the Mayo group. We present a novel series for further clinical and paraclinical refinement. METHODS: Serum and cerebrospinal fluid samples from a diagnostic laboratory were selected if found to be positive for GABA(B)R or AMPAR abs within a broad antineuronal ab panel. Data were retrospectively compiled. RESULTS: In 10 patients, we detected abs to GABA(B)R. Median age was 70 years. Five of them were diagnosed with small cell lung cancer (SCLC). Intrathecal GABA(B)R ab synthesis was found in all six patients with sufficient data available (median ab-index: 76.8). On MRI, we found bilateral mediotemporal and in two cases cortical abnormalities. EEG revealed encephalopathy, partly with epileptiform discharges. Five patients received immunotherapy, two patients tumour treatment and three both therapies. Three patients died, in five patients cognitive functions declined, one patient improved slightly and one patient fully recovered. AMPAR abs were detected in three patients with mnestic disturbances. Median age was 60.7 years. The only female patient was diagnosed with ovarian cancer. None of the patients had intrathecal ab synthesis. MRI findings showed bilateral mediotemporal abnormalities. EEG was normal in all patients. Two of the three immunologically treated patients improved, one patient stabilised on a low level. DISCUSSION: GABA(B)R and AMPAR abs are well associated with LE. GABA(B)R abs lead to severe clinical, neuroradiological and EEG abnormalities with poorer outcome.

How we treat primary central nervous system lymphoma.

Primary diffuse large B-cell (DLBCL) lymphoma of the central nervous system (CNS) (PCNSL) is a new lymphoma entity, recognized by the 2017 WHO classification of hematopoietic and lymphoid tumors. Unlike systemic DLBCL, the use of anthracycline-based chemotherapy combinations is associated with disappointing outcomes, due to low CNS bioavailability of related drugs. Therefore, international researchers investigated alternative strategies, mostly including drugs able to cross the blood-brain-barrier at low or high doses, with a progressive improvement in survival. Some effective chemotherapy combinations of high-dose methotrexate (HD-MTX) with alkylating agents and rituximab with or without cytarabine have been tested in international randomized trials and represent the induction treatment in everyday practice, with some variations among different geographical areas. In patients aged 70 years or younger, MATRix (HD-MTX/cytarabine/thiotepa/rituximab) chemotherapy followed by consolidative high-dose chemotherapy plus autologous stem cell transplantation or whole-brain irradiation has been associated with a significant improvement in overall survival. Other treatment options, such as non-myeloablative high-dose chemotherapy, oral drug maintenance, and some targeted drugs like ibrutinib or lenalidomide, are being tested in high-level international trials. These steps toward further effective treatments are motivated by an incessant search for less neurotoxic options. Thanks to international cooperation, we can affirm that PCNSL is a potentially curable tumor, especially in young patients. However, several questions remain unanswered: the optimal treatment for elderly patients as well as the management of intraocular and meningeal disease require further scientific efforts. Beside treatments, advances on molecular and radiological diagnostic tools will increase our knowledge of this disease, allowing the possibility to anticipate diagnosis and to better categorize patients' responses. This article analyzes the available literature in this setting and provides evidence-based recommendations for the management of PCNSL patients.

Quantitative muscle mass biomarkers are independent prognosis factors in primary central nervous system lymphoma: The role of L3-skeletal muscle index and temporal muscle thickness.

OBJECTIVE: To investigate the role of quantitative muscle biomarkers assessed with skeletal muscle index at the third lumbar vertebra (L3-SMI) and temporal muscle thickness (TMT) in predicting progression-free and overall survival in patients with primary central nervous system lymphoma (PCNSL) undergoing first-line high-dose methotrexate-based chemotherapy. METHODS: L3-SMI and TMT were calculated on abdominal CT and brain high-resolution 3D-T1-weighted MR images, respectively, using predefined validated methods. Standardized sex-specific cut-off values were used to divide patients in different risk categories. Kaplan-Meier plots were calculated, and survival analysis was performed using log-rank tests, univariate, and multivariable Cox-regression models, calculating hazard ratios (HR) and 95% confidence intervals (CI), also adjusting for potential confounders (age, sex, and performance status). RESULTS: Forty-three patients were included in this study. Median follow-up was 23 months (interquartile range 12-40); at median follow-up, rates of progression-free and overall survival for the cohort were 46% and 57%, respectively. Thirteen (30%) and 11 (26%) patients showed L3-SMI or TMT values below the predefined cut-offs. In Cox-regression multivariable analysis patients with low L3-SMI or TMT showed significantly worse progression-free (HR 4.40, 95% CI 1.66-11.61, p = 0.003; HR 4.40, 95% CI 1.68-11.49, p = 0.003, respectively) and overall survival (HR 3.16, 95% CI 1.09-9.11, p = 0.034; HR 4.93, 95% CI 1.78-13.65, p = 0.002, respectively) compared to patients with high L3-SMI or TMT. CONCLUSIONS: Quantitative muscle mass evaluation assessed by both L3-SMI and TMT is a promising tool to identify PCNSL patients at high risk of negative outcome. Confirmatory studies on larger independent series are warranted.

Primary follicular and marginal-zone lymphoma of the breast: clinical features, prognostic factors and outcome: a study by the International Extranodal Lymphoma Study Group.

BACKGROUND: Primary breast lymphoma (PBL) of low-grade histology is a rare disease. This multicentric retrospective study was carried out to determine clinical features, prognosis and relapse. PATIENTS AND METHODS: Patients with histologically proven, previously untreated follicular or marginal-zone PBL (MZL PBL) diagnosed from 1980 to 2003 were included in the study. Major end points were progression-free survival (PFS), overall survival (OS) and potential prognostic factors. RESULTS: We collected data on 60 cases of PBL [36 follicular and 24 marginal-zone lymphoma (MZL)]. Stage was I(E) or II(E) in 57 patients and IVE in three patients due to bilateral breast involvement. Surgery, chemotherapy and radiotherapy (RT), alone or in combination, were used as first-line treatments in 67%, 42% and 52% of patients, respectively. Overall response rate was 98%, with a 93% complete response rate. Five-year PFS were 56% for MZL and 49% for follicular PBL (P = 0.62). Relapses were mostly in distant sites (18 of 23 cases); no patients relapsed within RT fields. CONCLUSIONS: Our data showed an indolent behaviour of MZL PBL, comparable to other primary extranodal MZL. Conversely, patients with follicular PBL had inferior PFS and OS when compared with limited-stage nodal follicular non-Hodgkin's lymphomas, suggesting an adverse prognostic role of primary breast localisation in this histological subgroup.