Waldenstrom's Macroglobulinemia Research Articles

Clinical Spectrum of Monoclonal Protein and the Factors Associated with Lymphoplasmacytic Malignancies

Background: Monoclonal protein (MP) presents in various monoclonal gammopathies, ranging from benign conditions such as monoclonal gammopathy of undetermined significance (MGUS) to life-threatening conditions such as lymphoplasmacytic malignancies (LPMs), which include multiple myeloma (MM) and Waldenström macroglobulinemia (WM). Few studies have comprehensively assessed the clinical spectrum of MP and its factors associated with LPMs. This study aimed to determine the clinical spectrum of MP and identify factors associated with LPMs. Methods: This retrospective study included patients who were first tested for capillary electrophoresis (CEP) and identified as having MP between 2014 and 2023 at two university hospitals. Univariate (crude) and multivariate (adjusted) logistic regression analyses were performed to identify factors associated with LPMs. Results: Among the 1135 included patients with MP, 744 (65.6%) were diagnosed with LPMs and 391 (34.4%) with MGUS. Among the 391 patients with MGUS, 310 (79.3%) had at least 1 clinical association, including 204 with renal diseases, 35 with autoimmune diseases, 33 with chronic liver diseases, 22 with hematologic diseases, and 96 with other conditions. Multivariate analyses indicated that LPMs were associated with female sex (OR = 2.08), lower age (OR = 0.95), higher MP level (OR = 3.53), an abnormal FLC ratio (OR = 6.15), lower hemoglobin level (OR = 0.82), and higher total calcium level (OR = 1.81) (all p < 0.05). Conclusions: This study provides insight into the distribution of MPs and their clinical association with MGUS and identifies factors related to LPM. These can help clinicians manage patients more effectively in the early stages of these conditions.

Six-year follow-up of phase II study exploring chemo-free treatment association with idelalisib and obinutuzumab in symptomatic relapsed/ refractory patients with Waldenström's macroglobulinemia.

We present the 6-year update of a phase 2 study evaluating the combination of obinutuzumab and idelalisib in relapse/refractory Waldenstrom macroglobulinemia. The results of the REMODEL trial demonstrated interesting efficacy in a high-risk genotype profile population. The primary endpoint was achieved with a median PFS of 25.4months (95% CI, 15.7 to 29.0). However, a major limitation of idelalisib is its toxicity. With a median follow-up of 70.9months, median OS was still not reached, and 5-year OS was 72.9% (95% CI, 61.3 to 86.6). We confirm that CXCR4 mutations had no impact on PFS or OS. However, TP53 mutated patients had shorter OS. At the time of analysis, six patients are alive without relapse and 40 had progressive disease. Among the 38 patients who received a new treatment, the median time to second progression was not reached in ibrutinib treated patients (n = 17) versus 30.8months in patients treated with other options (95% CI, 16.9 to NA), p = 0.005. With longer follow-up our prospective study is the first to show an impact of TP53 mutations in patients treated with fixed duration chemo-free regimen leading to a significant shorter OS in this population. Moreover, ibrutinib remains an effective treatment after this combination. This study was registered on the clinicaltrial.gov web (NCT02962401, November 9, 2016).

Intracapillary monoclonal IgM deposits disease with massive pseudothrombi: A clinicopathologic study of 4 cases and literature review.

Intracapillary monoclonal IgM deposits disease (ICMDD) has long been considered a hallmark of Waldenström macroglobulinemia (WM) nephropathy. Intracapillary immunoglobulin thrombi are the characteristic features of cryoglobulinemic glomerulonephritis. Here, we reported 4 cases of ICMDD with massive pseudothrombi but without WM or cryoglobulinemia. We retrospectively analyzed the clinical and pathologic features of patients diagnosed with ICMDD with massive pseudothrombi. A total of 4 patients (2 men and 2 women) aged 62 to 73 years were enrolled in this study. Microscopic hematuria, edema, and renal insufficiency were present in all patients, along with low serum C3 and C4 in 2 patients. Hematologic examination showed abnormal serum free light chain ratios in all patients and high levels of serum IgM in 3 patients. IgM-κ monoclonal band was identified by serum immunofixation electrophoresis in 3 patients. One patient was diagnosed with small B-cell lymphoma by bone marrow aspiration. Renal biopsy specimen showed massive periodic acid-Schiff-positive hyaline thrombi in the glomerular capillary lumens and also less mesangial, subendothelial, and subepithelial deposits on light microscopy. Immunofluorescence indicated positive staining for IgM (++) and κ light chain staining in the glomerular capillary lumens, capillary walls, and mesangium in all patients. By electron microscopy, the glomerular capillary lumens were filled with homogeneous high-electron-dense deposits without substructure. Two patients were treated with prednisone combined with cyclophosphamide, and 2 received plasma cell-targeted chemotherapy. One patient achieved partial renal remission. Intracapillary monoclonal IgM deposits disease is a rare disease and not always related to WM. Most patients have IgM monoclonal immunoglobulinemia; renal biopsy specimens mainly show a large number of pseudothrombi in the glomerular capillary lumens. Cyclophosphamide is effective in some patients.

Extramedullary disease in Waldenström macroglobulinemia: A population‐based observational study

AbstractIntroduction: Extramedullary disease (EMD) is a rare manifestation of Waldenström macroglobulinemia (WM), and its clinical and prognostic implications are poorly understood. Methods: In this single‐center study, we investigated the clinical significance of EMD in a cohort of 469 WM patients. Results: EMD was identified in 30 (6.4%) patients, with the central nervous system, kidneys, and lungs being the most frequently affected sites. The cumulative incidence of EMD was 12.6% at 15 years. Median overall survival rates at 5 and 10 years for patients with EMD were 63% and 37%, respectively. Conclusion: Our findings indicate a persistent risk of EMD throughout the disease course, with no significant impact on long‐term survival.

Mavorixafor: A spotlight on the clinical aspects and prospects of the first USFDA-approved treatment for the primary immunodeficiency WHIM syndrome

WHIM syndrome (WHIMS) is an extremely rare, severe, and potentially fatal genetic condition that affects the immune system, leading to warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM). Effective therapy for WHIMS requires regular monitoring, medical intervention, and a collaborative approach to treatment. Due to the limited therapeutic options, addressing WHIMS is an unmet medical need. The United States Food and Drug Administration (USFDA) recently granted approval for mavorixafor as the first treatment for WHIMS. This review focuses on the pharmacological characteristics, clinical investigations, associated inventions, and prospects of mavorixafor. The literature for this article was searched on PubMed, reputable websites (USFDA and X4 Pharmaceuticals) and free patent databases like Espacenet. WHIMS is distinguished by severe neutropenia and hypogammaglobulinemia, which increases the risk of developing cancer. Mavorixafor enhances the movement of neutrophils and lymphocytes from the bone marrow (BM) to the bloodstream. Hence, it could be beneficial for managing medical illnesses characterized by a decrease in the quantity of neutrophils and lymphocytes in the bloodstream. X4 Pharmaceuticals has submitted patent applications for the utilization of mavorixafor in the treatment of diverse cancer types, inflammatory ailments, B-cell dysfunction, Waldenstrom's macroglobulinemia, and primary immunodeficiency disorders. This suggests that mavorixafor can effectively treat various disorders either alone or when used in conjunction with other medications. It will be intriguing to observe the future approvals of mavorixafor for various disorders.Keywords: Mavorixafor; WHIM syndrome; Cancer; Immunodeficiency; Patent; Prospect

Waldenstrom's Macroglobulinemia: A Case Report

Waldenström's macroglobulinemia (WM) is a rare, slow-growing hematologic malignancy marked by elevated levels of monoclonal immunoglobulin M (IgM) and bone marrow infiltration by lymphoplasmacytic cells. This case details a 72-year-old man who, during a pre-anesthetic consultation for lumbar spinal stenosis surgery, presented with neurological symptoms, fatigue, and headaches. Examination revealed pallor, and laboratory tests indicated anemia and an elevated erythrocyte sedimentation rate. Serum protein electrophoresis identified a monoclonal IgM spike, and bone marrow aspiration showed significant infiltration by small lymphoid cells, lymphoplasmacytoid cells, and plasma cells. WM was confirmed, and the patient was treated with dexamethasone, rituximab, and cyclophosphamide, with positive follow-up progress. This case underscores the importance of considering WM in the differential diagnosis for patients with unexplained anemia and elevated IgM levels, highlighting the need for timely diagnosis and treatment to manage potential complications.

Determination of MYD88 and CXCR4 mutation for clinical detection and their significance in Waldenström macroglobulinemia.

This study aims to explore the incidence and clinical features of MYD88 and CXCR4 mutations in patients with Waldenström macroglobulinemia (WM) and determine the optimal method for routine clinical practice. Additionally, we seek to evaluate the prognostic significance of these features across various therapeutic backgrounds [cytotoxic group, the Rituximab/Bortezomib-based group, and the Bruton's tyrosine kinase inhibitor (BTKi) group]. 385 symptomatic WM patients were analyzed for MYD88 and CXCR4 mutations using Sanger sequencing, next-generation sequencing (NGS), allele-specific quantitative polymerase chain reaction (AS-PCR), and/or droplet digital PCR (ddPCR). The overall MYD88 mutation rate was 87.8%, relatively lower than that in Western cohort. Both AS-PCR and ddPCR demonstrated high sensitivity in unsorted samples, detecting 98.5% and 97.7% of mutations, respectively, including those with low tumor burdens. The total CXCR4 mutation rate was 30.9%, with NGS exhibiting the highest sensitivity of 78.0%. CXCR4 mutation was significantly linked to shorter OS only within the BTKi treatment group. The multivariate analysis indicated that MYD88 and CXCR4 mutations were not independent prognostic factors in the non-BTKi group when considering IPSSWM clinical staging. However, in the BTKi treatment group, these mutations emerged as independent adverse prognostic factors, overshadowing the prognostic significance of IPSSWM classification (MYD88: HR=0.229, P=0.030; CXCR4: HR=3.349, P=0.012). Testing for MYD88 mutations using AS-PCR or ddPCR in unsorted samples is viable for routine clinical practice. Under BTKi treatment, MYD88 and CXCR4 mutations hold greater prognostic importance than IPSSWM staging in WM.

CORRIGENDUM: Optical coherence tomography angiography features in Waldenström macroglobulinemia patients without Hyperviscosity syndrome: A pilot prospective study

PurposeTo evaluate the retinal vessel density (VD) with optical coherence tomography angiography (OCTA) in asymptomatic patients affected by Waldenström macroglobulinemia (WM) without hyperviscosity syndrome (HVS) and to highlight the presence of microvascular damage in theese clinically asymptomatic WD patients. DesignProspective study. MethodsA total of 43 eyes from 43 WM patients (24 females, 19 males, mean age 55.1 ± 13.6 years) were enrolled from January 2023 to December 2023 in the Eye Clinic of the University of Naples Federico II. .Along with WM patients, 40 healthy subjects (HS) (20 females, 20 males, mean age 52.3 ± 15.6 years) with a normal ophthalmic examination and no history of intraocular surgery or retinal pathologic features were included as control group All patients and controls underwent OCTA. ResultsThe two groups were not significantly different for age and sex Visual acuity examination showed no statistically significant difference in BCVA between controls and patients Compared to HS, WD patients showed lower VD values in the SCP in the whole image (47.95 ± 5.17 % vs. 52.99 ± 2.52%; p < 0.001), as well as in the parafovea (53.01 ± 6.69 % vs. 55.30 ± 2.61%; p = 0.002), and fovea (21.38 ± 9.01 % vs. 30.31 ± 5.84 %; p < 0.001). On the other hand, in the DCP VD values were significantly higher in patients compared to controls in the whole image (55.82 ± 8.07 % vs. 50.83 ± 5.46%; p = 0.005), as well as in the parafovea (56.76 ± 6.26 % vs. 52.59 ± 5.46%; p = 0.001), and fovea (38.75 ± 8.59 % vs. 33.43 ± 8.68 %; p < 0.001). ConclusionThe finding that OCTA confirmed the presence of widespread microvascular damage in WD patients clinically silent. Thus, OCTA is a safe rapid imaging technique that could represent a valid biomarker of systemic vascular dysfunction.

Prognostic impact of nodal involvement in Waldenström macroglobulinaemia.

The clinical and prognostic implications of nodal involvement (NI) in Waldenström macroglobulinaemia (WM) are largely unknown. In this study, we explored the impact of NI on clinical presentation and outcome in a population-based cohort of 469 patients with WM, consecutively diagnosed between 2000 and 2022. NI was detected in 34% of patients and was associated with symptomatic disease, adverse prognostic factors, an increased risk of transformation, and lymphoma-related death. Our findings indicate that NI is of prognostic significance in WM, suggesting a need for enhanced surveillance in these patients.

Acute Tubulointerstitial Nephritis with Membranous Nephropathy in a Patient with Newly Diagnosed Waldenstrom Macroglobulinemia

Acute Tubulointerstitial Nephritis with Membranous Nephropathy in a Patient with Newly Diagnosed Waldenstrom Macroglobulinemia

Patients with Waldenström macroglobulinemia have impaired platelet and coagulation function

AbstractClinical features in patients with the B-cell lymphoma, Waldenström macroglobulinemia (WM), include cytopenias, immunoglobulin M (IgM)–mediated hyperviscosity, fatigue, bleeding, and bruising. Therapeutics such as Bruton's tyrosine kinase inhibitors (BTKis) exacerbate bleeding risk. Abnormal hemostasis arising from platelet dysfunction, altered coagulation or vascular impairment have not yet been investigated in patients with WM. Therefore, this study aimed to evaluate hemostatic dysfunction in samples from these patients. Whole blood (WB) samples were collected from 14 patients with WM not receiving therapy, 5 patients receiving BTKis and 15 healthy donors (HDs). Platelet receptor levels and reticulation were measured by flow cytometry, plasma thrombin generation with or without platelets by fluorescence resonance energy transfer assay, WB clotting potential by rotational thromboelastometry, and plasma soluble glycoprotein VI (sGPVI) and serum thrombopoietin (TPO) by enzyme-linked immunosorbent assay. Donor platelet spreading, aggregation, and ability to accelerate thrombin generation in the presence of WM-derived IgM were assessed. WM platelet receptor levels, responses to physiological agonists, and plasma sGPVI were within normal ranges. WM platelets had reduced reticulation (P = .0012) whereas serum TPO levels were increased (P = .0040). WM plasma displayed slower thrombin generation (P = .0080) and WM platelets contributed less to endogenous thrombin potential (ETP; P = .0312). HD plasma or platelets incubated with IgM (50-60 mg/mL) displayed reduced spreading (P = .0002), aggregation (P < .0001), and ETP (P = .0081). Thus, alterations to thrombin potential and WB coagulation were detected in WM samples. WM IgM significantly impaired hemostasis in vitro. Platelet and coagulation properties are disturbed in patients with well-managed WM.

An unusual case of Waldenstrom Macroglobulinemia with Mott cell differentiation in bone marrow - orchard of flower appearance.

An unusual case of Waldenstrom Macroglobulinemia with Mott cell differentiation in bone marrow - orchard of flower appearance.

Personalized dose selection for the first Waldenström macroglobulinemia patient on the PRECISE CURATE.AI trial

The digital revolution in healthcare, amplified by the COVID-19 pandemic and artificial intelligence (AI) advances, has led to a surge in the development of digital technologies. However, integrating digital health solutions, especially AI-based ones, in rare diseases like Waldenström macroglobulinemia (WM) remains challenging due to limited data, among other factors. CURATE.AI, a clinical decision support system, offers an alternative to big data approaches by calibrating individual treatment profiles based on that individual’s data alone. We present a case study from the PRECISE CURATE.AI trial with a WM patient, where, over two years, CURATE.AI provided dynamic Ibrutinib dose recommendations to clinicians (users) aimed at achieving optimal IgM levels. An 80-year-old male with newly diagnosed WM requiring treatment due to anemia was recruited to the trial for CURATE.AI-based dosing of the Bruton tyrosine kinase inhibitor Ibrutinib. The primary and secondary outcome measures were focused on scientific and logistical feasibility. Preliminary results underscore the platform’s potential in enhancing user and patient engagement, in addition to clinical efficacy. Based on a two-year-long patient enrollment into the CURATE.AI-augmented treatment, this study showcases how AI-enabled tools can support the management of rare diseases, emphasizing the integration of AI to enhance personalized therapy.

Hyperviscosity-Related Retinopathy and Serous Macular Detachment in Waldenstrӧm Macroglobulinemia Managed With Zanubrutinib

Waldenstrom macroglobulinemia (WM) is an uncommon lymphoproliferative B-cell disorder characterized by overproduction of monoclonal...

PembroWM: A phase II trial to investigate the safety and efficacy of rituximab and pembrolizumab in relapsed/refractory Waldenström's Macroglobulinaemia.

The optimal therapeutic approach for relapsed/refractory (R/R) Waldenström's Macroglobulinaemia (WM) has not been clearly defined, especially after treatment with chemoimmunotherapy (CIT) and covalent Bruton's tyrosine kinase inhibitors (cBTKi). The PembroWM trial is a multi-centre, phase II, single-arm study assessing the safety, tolerability and efficacy of rituximab with pembrolizumab in R/R WM patients who had received at least one prior line of treatment, with all having relapsed post-CIT and most also exposed to cBTKi. A total of 17 patients were enrolled, with a median age of 70, and median of three prior lines of therapy with 15 either refractory or intolerant of a cBTKi. A significant proportion was identified as genomically high risk with BTKC481, CXCR4 and MYD88 L265P wild-type aberrations. Twenty-four-week overall response rate was 50% (60% CI 39.3%-60.7%), and median duration of response was 11.6 months (IQR: 6.3-17). The median progression-free survival was 13.6 months (95% CI 3-19.8), and the median overall survival (OS) was not reached. Treatment was well tolerated, with minimal numbers of immune-mediated AEs typically seen with checkpoint inhibitors. PembroWM is the first study to evaluate the feasibility of PD-1 axis modulation in WM and has shown that in combination with Rituximab the combination is safe and deliverable.

Unlocking the therapeutic potential of selective CDK7 and BRD4 Inhibition against multiple myeloma cell growth.

Multiple myeloma (MM) is a plasma cell malignancy considered incurable despite the recent therapeutic advances. Effective targeted therapies are therefore needed. Our previous studies proved that inhibiting CDK7 impairs the cell cycle and metabolic programs by disrupting E2F1 and MYC transcriptional activities, making it an appealing therapeutic target for MM. Given that CDK7 and BRD4 operate in two distinct regulatory axes in MM, we hypothesized that targeting these two complementary pathways simultaneously would lead to a deeper and more durable response. Indeed, combination therapy had superior activity against MM cell growth and viability, and induced apoptosis to a greater extent than single-agent therapy in both cell lines and patient cells. This synergistic activity was also observed in Waldenström's Macroglobulinemia (WM) cells and with other inhibitors of E2F1 activity. Dual inhibition effectively impaired the MYC and E2F transcriptional programs and MM tumor growth and progression in xenograft animal models, providing evidence for combination therapy's potential as a therapeutic strategy in MM and WM.

A retrospective observational study of ibrutinib in chronic lymphocytic leukaemia in a real-life setting in France using the national claims database (OSIRIS)

BackgroundIbrutinib is a Bruton’s tyrosine kinase inhibitor indicated for the first-line treatment and relapse of chronic lymphocytic leukaemia (CLL), Waldenström’s macroglobulinemia (WM) and mantle cell lymphoma (MCL). This study aimed to describe the characteristics of CLL patients treated with ibrutinib and its effectiveness, safety, and treatment pattern in real life.MethodsAll patients covered by the general health scheme (approximately 80% of the French population) with a first ibrutinib dispensation from August 1, 2017 (date of reimbursement in France) to December 31, 2020, were identified in the French National Health Insurance database (SNDS). An algorithm was developed to identify the disease (CLL, MCL or WM) for which ibrutinib was prescribed. This article focused on CLL patients. The time to next treatment (TTNT) was plotted using Kaplan‒Meier curves.ResultsDuring this period, 6,083 patients initiated ibrutinib, among whom 2,771 (45.6%) patients had CLL (mean age of 74 years; 61% of men). At ibrutinib initiation, 46.6% of patients had a cardiovascular comorbidity. Most patients (91.7%) were not hospitalized during the exposure period for one of the cardiovascular or bleeding events studied. Hospitalizations were more frequent in patients with a cardiovascular comorbidity (5.9% versus 11.0%, p-value < 0.0001) and aged over 70 (5.9% versus 9.4%, p-value < 0.0001). The median TTNT was not reached.ConclusionThis is one of the largest cohorts of ibrutinib-treated patients in the world. The profile of CLL patients treated with ibrutinib was in accordance with the marketing authorization and reimbursement. This study confirmed effectiveness and safety data.

Optical coherence tomography angiography features in Waldenström macroglobulinemia patients without Hyperviscosity syndrome: A pilot prospective study

PurposeTo evaluate the retinal vessel density (VD) with optical coherence tomography angiography (OCTA) in asymptomatic patients affected by Waldenström macroglobulinemia (WM) without hyperviscosity syndrome (HVS) and to highlight the presence of microvascular damage in theese clinically asymptomatic WD patients. DesignProspective study. MethodsA total of 43 eyes from 43 WM patients (24 females, 19 males, mean age 55.1 ± 13.6 years) were enrolled from January 2023 to December 2023 in the Eye Clinic of the University of Naples Federico II. Along with WM patients, 40 healthy subjects (HS) (20 females, 20 males, mean age 52.3 ± 15.6 years) with a normal ophthalmic examination and no history of intraocular surgery or retinal pathologic features were included as control group All patients and controls underwent OCTA ResultsThe two groups were not significantly different for age and sex Visual acuity examination showed no statistically significant difference in BCVA between controls and patients Compared to HS, WD patients showed lower VD values in the SCP in the whole image (47.95 ± 5.17% vs. 52.99 ± 2.52 %; p < 0.001), as well as in the parafovea (53.01 ± 6.69% vs. 55.30 ± 2.61 %; p = 0.002), and fovea (21.38 ± 9.01% vs. 30.31 ± 5.84 %; p < 0.0001). On the other hand, in the DCP VD values were significantly higher in patients compared to controls in the whole image (55.82 ± 8.07% vs. 50.83 ± 5.46 %; p = 0.005), as well as in the parafovea (56.76 ± 6.26% vs. 52.59 ± 5.46 %; p = 0.0001), and fovea (38.75 ± 8.59% vs. 33.43 ± 8.68 %; p < 0.0001). ConclusionThe finding that OCTA confirmed the presence of widespread microvascular damage in WD patients clinically silent. Thus, OCTA is a safe rapid imaging technique that could represent a valid biomarker of systemic vascular dysfunction.

Revealing the Role of the Arg and Lys in Shifting Paradigm from BTK Selective Inhibition to the BTK/HCK Dual Inhibition - Delving into the Inhibitory Activity of KIN-8194 against BTK, and HCK in the Treatment of Mutated BTKCys481 Waldenström Macroglobulinemia: A Computational Approach.

Despite the early success of Bruton's tyrosine kinase (BTK) inhibitors in the treatment of Waldenström macroglobulinemia (WM), these single-target drug therapies have limitations in their clinical applications, such as drug resistance. Several alternative strategies have been developed, including the use of dual inhibitors, to maximize the therapeutic potential of these drugs. Recently, the pharmacological activity of KIN-8194 was repurposed to serve as a 'dual-target' inhibitor of BTK and Hematopoietic Cell Kinase (HCK). However, the structural dual inhibitory mechanism remains unexplored, hence the aim of this study. Conducting predictive pharmacokinetic profiling of KIN-8194, as well as demonstrating a comparative structural mechanism of inhibition against the above-mentioned enzymes. Our results revealed favourable binding affinities of -20.17 kcal/mol, and -35.82 kcal/mol for KIN-8194 towards HCK and BTK, respectively. Catalytic residues Arg137/174 and Lys42/170 in BTK and Arg303 and Lys75/173/244/247 in HCK were identified as crucial mediators of the dual binding mechanism of KIN-8194, corroborated by high per-residue energy contributions and consistent high-affinity interactions of these residues. Prediction of the pharmacokinetics and physicochemical properties of KIN-8194 further established its inhibitory potential, evidenced by the favourable absorption, metabolism, excretion, and minimal toxicity properties. Structurally, KIN-8194 impacted the stability, flexibility, solvent-accessible surface area, and rigidity of BTK and HCK, characterized by various alterations observed in the bound and unbound structures, which proved enough to disrupt their biological function. These structural insights provided a baseline for the understanding of the dual inhibitory activity of KIN- 8194. Establishing the cruciality of the interactions between the KIN-8194 and Arg and Lys residues could guide the structure-based design of novel dual BTK/HCK inhibitors with improved therapeutic activities.

Waldenström Macroglobulinemia - A State-of-the-Art Review: Part 1: Epidemiology, Pathogenesis, Clinicopathologic Characteristics, Differential Diagnosis, Risk Stratification, and Clinical Problems.

Waldenström macroglobulinemia (WM) is an infrequent variant of lymphoma, classified as a B-cell malignancy identified by the presence of IgM paraprotein, infiltration of clonal, small lymphoplasmacytic B cells in the bone marrow, and the MYD88 L265P mutation, which is observed in over 90% of cases. The direct invasion of the malignant cells into tissues like lymph nodes and spleen, along with the immune response related to IgM, can also lead to various health complications, such as cytopenias, hyperviscosity, peripheral neuropathy, amyloidosis, and Bing-Neel syndrome. Chemoimmunotherapy has historically been considered the preferred treatment for WM, wherein the combination of rituximab and nucleoside analogs, alkylating drugs, or proteasome inhibitors has exhibited notable efficacy in inhibiting tumor growth. Recent studies have provided evidence that Bruton Tyrosine Kinase inhibitors (BTKI), either used independently or in conjunction with other drugs, have been shown to be effective and safe in the treatment of WM. The disease is considered to be non-curable, with a median life expectancy of 10 to 12 years.