Bing Neel Syndrome in a Previously Untreated Patient With Waldenström's Macroglobulinemia: Contribution of MYD88 L265P Mutation on Cerebrospinal Fluid

Bing-Neel Syndrome, a Rare Presentation of Waldenström Macroglobulinemia—A Multicenter Report by the Polish Lymphoma Research Group

Bing-Neel syndrome (BNS) is a rare presentation of Waldenström macroglobulinemia (WM). BNS is a consequence of the central nervous system (CNS) involvement by lymphoplasmacytic lymphoma (LPL) and, rarely, the peripheral nervous system. The data on BNS are extremely scarce. Therefore, we performed a multicenter retrospective analysis of BNS patients diagnosed and treated in centers aligned with the Polish Lymphoma Research Group. The analysis covers the years 2014–2021. Eleven patients were included, 55% females and the median age at BNS diagnosis was 61 years. The median time from WM to BNS was 3.5 years; 27% of patients did have a diagnosis of WM and BNS made simultaneously or within 30 days from each other. Isolated parenchymal involvement was the least frequent (20%). Patients were treated with different regimens, mostly able to cross the blood-brain barrier, including 18% treated with ibrutinib first line. The cumulative objective response to treatment was 73%. With the median follow-up of 20 months (95% CI, 2–32), the 36-month estimates were: overall survival (OS) 47%, progression-free survival (PFS) 33%, and cumulative incidence of BNS-associated death 41%. The performance status according to ECOG was significant for PFS (HR = 7.79) and the hemoglobin concentration below 11 g/dL was correlated with PFS. To conclude, BNS is a very rare manifestation of WM. It is associated with a poor outcome with most patients succumbing to BNS.

From Biology to Treatment of Monoclonal Gammopathies of Neurological Significance

Monoclonal gammopathy and peripheral neuropathy are common diseases of elderly patients, and almost 10% of patients with neuropathy of unknown cause have paraprotein. However, growing evidence suggests that several hematological malignancies synthesize and release monoclonal proteins that damage the peripheral nervous system through different mechanisms. The spectrum of the disease varies from mild to rapidly progressive symptoms, sometimes affecting not only sensory nerve fibers, but also motor and autonomic fibers. Therefore, a multidisciplinary approach, mainly between hematologists and neurologists, is recommended in order to establish the correct diagnosis of monoclonal gammopathy of neurological significance and to tailor therapy based on specific genetic mutations. In this review, we summarize the spectrum of monoclonal gammopathies of neurological significance, their distinctive clinical and neurophysiological phenotypes, the most relevant pathophysiological events and new therapeutic approaches.

Monitoring of MYD88 L265P mutation by droplet digital polymerase chain reaction for prediction of early relapse in a patient with Bing-Neel syndrome

Bing-Neel syndrome (BNS) is a rare neurologic complication of lymphoplasmacytic lymphoma (LPL) characterized by direct infiltration of lymphoplasmacytic cells (LPCs). Although no standard treatment has yet been established, patients with BNS harboring the MYD88 L265P mutation have been reported to respond favorably to ibrutinib, which can cross the blood-brain barrier and trigger apoptosis of MYD88 L265P-positive LPCs. However, it is still unclear whether monitoring of MYD88 L265P mutation status would be useful for predicting relapse/progression or for assisting diagnosis and evaluating response to chemotherapy. Here, we report the case of a patient with BNS receiving ibrutinib in whom we detected relapse early by monitoring for molecular residual disease (MRD) based on the presence of the MYD88 L265P mutation in cerebrospinal fluid (CSF) on droplet digital polymerase chain reaction assay. Persistent MRD increased 2 weeks before the onset of relapse symptoms without any abnormal imaging findings or evidence of clonal LPCs on CSF cytology, flow cytometry analysis, or immunofixation electrophoresis. Our findings suggest that an increase in MRD levels is correlated with relapse in patients with BNS.

An Autopsy Case of Bing-Neel Syndrome: Discrepancy between the Radiological and Pathological Findings

A 64-year-old man previously diagnosed with Waldenstrom's macroglobulinemia presented to our hospital with confusion. Magnetic resonance imaging (MRI) revealed diffuse meningeal enhancement. The patient was diagnosed with Bing-Neel syndrome (BNS) based on an elevated IgM index and the presence of monoclonal IgM protein, as detected by immunofixation electrophoresis of the cerebrospinal fluid. The patient underwent intrathecal and systemic chemotherapy but ultimately died of pneumonia. An autopsy revealed extensive meningeal and perivascular infiltration by malignant cells throughout the brain and spine. Thus, BNS may cause more extensive malignant infiltration into the central nervous system than is revealed by MRI.

Investigation and management of IgM and Waldenström-associated peripheral neuropathies: recommendations from the IWWM-8 consensus panel

Paraproteinaemic neuropathies are a heterogeneous group of disorders most frequently associated with IgM monoclonal gammopathies including Waldenström macroglobulinaemia (WM). Their consequences are significant for affected patients, and their management challenging for their physicians. The variability in clinical presentation and time course hamper classification and management. The indications for invasive investigations such as cerebrospinal fluid analysis, nerve conduction tests and sensory nerve biopsies are unclear, and the optimum way to measure clinical response to treatment unknown. When to intervene and and how to treat, also present challenges to physicians. As part of its latest deliberations at the International Workshops on WM (IWWM) in London, UK (August 2014), the IWWM8 panel have proposed a consensus approach to the diagnosis and management of peripheral neuropathies associated with IgM monoclonal gammopathies, including WM. Importantly, a consensus regarding the use of clinical outcome measures and recommended models of care for this group of patients is discussed, as well as appropriate treatment interventions.

Guideline for the diagnosis, treatment and response criteria for Bing-Neel syndrome

Bing Neel syndrome is a rare disease manifestation of Waldenström's macroglobulinemia that results from infiltration of the central nervous system by malignant lymphoplasmacytic cells. In this guideline we describe the clinical symptoms, as well as the appropriate laboratory and radiological studies, that can aid in the diagnosis. The presentation of Bing Neel syndrome may be very diverse, and includes headaches, cognitive deficits, paresis, and psychiatric symptoms. The syndrome can present in patients with known Waldenström's macroglobulinemia, even in the absence of systemic progression, but also in previously undiagnosed patients. Diagnostic work-up should include cerebral spinal fluid analysis with multiparameter flow cytometry to establish B-cell clonality, protein electrophoresis and immunofixation for the detection and classification of a monoclonal protein as well as molecular diagnostic testing for immunoglobulin gene rearrangement and mutated MYD88. MRI of the brain and spinal cord is also essential. The second challenge is to expand our knowledge of prognosis and treatment outcome. Prospective clinical trials on Bing Neel syndrome patients that employ uniform treatment along with appropriate laboratory cerebral spinal fluid assessments and standardized MRI protocols will be invaluable, constituting a significant step forward in delineating treatment outcome for this intriguing disease manifestation.