Form Of Plasma Cell Dyscrasia Research Articles

Plasma Cell Leukemia with atypical CCND1/IGH fusion and Monocytoid morphology; A Rare Case Finding

Abstract Introduction/Objective Plasma cell leukemia (PCL) is a rare and aggressive form of plasma cell dyscrasia, often presenting as a variant of multiple myeloma (MM). It is characterized by the presence of ≥5% circulating plasma cells in peripheral blood, either as a primary or secondary manifestation of MM. Methods/Case Report Our case is of a 77-year-old male who presented with epigastric tenderness and bi-basilar crackles. Laboratory results showed severe hypercalcemia, elevated creatinine, leukocytosis, and elevated absolute neutrophil and lymphocyte counts. Imaging revealed widespread lytic lesions in the ribs, scapulae, thoracolumbar spine, and bony pelvis. Peripheral blood smear showed significant macrocytic anemia with rare polychromatophilic cells, numerous immature plasmacytoid cells (>20% of total cell count) and monocytoid morphology. Flow cytometry confirmed a population of monotypic plasma cells (28% of total cells). Bone marrow biopsy revealed a hypercellular plasma cell infiltrate with complex clonal karyotypic abnormalities, including the t(11;14)(q13;q32), rearrangements of 1p, and gain of 1q. FISH analysis showed an atypical CCND1/IGH fusion in 57% of cells, with one fusion, two orange (CCND1), and two green (IGH) signals. The case presented demonstrates a rare instance of an atypical CCND1/IGH fusion in plasma cell leukemia with monocytoid morphology, which poses diagnostic challenges. Prompt and accurate diagnosis is essential for managing the condition, given its consistently poor prognosis despite advancements in therapy over the past decade. Results (if a Case Study enter NA) NA Conclusion Our case highlights the importance of recognizing rare molecular abnormalities in PCL and suggests that further research into the molecular pathways involved in the disease is needed to improve diagnosis, treatment options and clinical outcomes.

Current Status on Management of Primary Plasma Cell Leukemia.

Plasma Cell Leukemia (PCL) is a very rare and highly aggressive form of plasma cell dyscrasia. This review seeks to evaluate the outcomes of PCL in the context of combination novel agent therapy and stem cell transplant (SCT) protocols. The diagnostic criteria for PCL have now evolved to include patients with 5% circulating PC. While management remains challenging, the incorporation of novel agent-based induction regimen has significantly improved early mortality and reduced attrition of patients proceeding to SCT. In recent prospective clinical trials, patients with PCL demonstrated an overall response rates of 69% to 86%, with progression-free and overall survival ranging from 13.8 to 15.5months and 24.8 to 36.3months, respectively. B-cell lymphoma 2 (BCL2) inhibitors, such as venetoclax present a targeted intervention opportunity for patients with PCL with t(11;14). Dedicated clinical trials tailored to PCL are crucial, integrating newer therapies in the frontline setting to further optimize responses and enhance overall outcomes.

Monoclonal gammopathy of clinical signifi cance with osteosclerotic lesions - a case report and a literature review.

Multiple myeloma is a common plasma cell neoplasia usually accompanied by the formation of osteolytic foci, whereas osteosclerotic myeloma is a very rare form of plasma cell dyscrasia. When osteosclerotic myeloma is detected, osteosclerotic foci are usually part of the POEMS syndrome. Osteosclerotic myeloma without other manifestations of the POEMS syndrome is an unusual finding. In a 46-year-old woman, osteosclerotic changes of the temporoparietal region caused soft tissue induration over this lesion, which initiated further investigation. Imaging studies subsequently showed multiple osteosclerotic foci in the skull. Examination of blood proteins revealed 8 g/L of IgG-lambda monoclonal immunoglobulin, subclass IgG1. In search of the cause of the osteosclerotic changes, FDG-PET/CT was performed, which revealed no FDG accumulation, i.e., no other tumor (breast or stomach cancer). Low-dose CT showed irregular bone structure, but not significant osteolytic or osteosclerotic foci. To map the extent of osteosclerotic changes, NaF-PET/CT imagination followed, which revealed multiple spots with high fluoride accumulation. A parietal bone biopsy showed osteosclerosis with minor clonal plasma cell infiltration. Trepanobioptic bone marrow sampling revealed an infiltration of bone marrow with atypical plasma cells in 8%. Flow-cytometric examination of bone marrow showed 0,37% of plasma cells, however predominantly (91%) clonal with lambda expression. MRI of the brain identified asymptomatic meningeal thickening. There was no evidence of POEMS syndrome in the patient; thus, we concluded the diagnosis as monoclonal gammopathy of clinical significance with osteosclerosis which was previously termed osteosclerotic multiple myeloma. Monoclonal gammopathy of clinical significance (MGCS) with osteosclerotic skeletal changes, documented on CT and multiple foci with intensive osteoneogenesis, documented on NaF-PET/CT without evidence of POEMS syndrome, is an extremely rare form of plasma cell dyscrasia. This publication documents the unique clinical manifestations of IgG-lambda type plasma cell proliferation without signs of POEMS syndrome and the role of NaF-PET/CT imaging. Classification of this disease as MGSC with osteosclerotic manifestations is more consistent with the indolent nature of the disease with a significantly better prognosis, compared with multiple myeloma.

Long-Term Outcomes of Autologous Stem Cell Transplantation in Patients with Newly Diagnosed POEMS Syndrome

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare form of plasma cell dyscrasia often treated with high-dose chemotherapy and autologous stem cell transplantation (ASCT). ASCT has resulted in satisfactory and sustained therapeutic outcomes. However, a substantial number of patients eventually experience disease progression, requiring second-line treatment. Therefore, it would be of further benefit to identify patients who will acquire the best long-term survival after ASCT. The aim of this study was to fully reveal the outcomes of patients undergoing ASCT in a large series with long-term follow-up. Long-term outcomes of 239 patients with newly diagnosed POEMS syndrome undergoing ASCT at a single center were evaluated retrospectively. Rates of hematologic complete response (CRH) and vascular endothelial growth factor (VEGF) complete response (CRV) were 57.3% and 68.6%, respectively, with 90.5% of patients achieving an overall clinical response. At a median follow-up of 94 months, the 5-year overall survival (OS) rate was 92.8%, and the 5-year time to next-line treatment (TTNT) rate was 72.2% (median TTNT, 96 months). Patients achieving CRH (5-year TTNT rate, 82.5% versus 60.7%; P < .0001) or CRV (5-year TTNT rate 83.7% versus 54.2%; P < .0001) had better survival outcomes compared to non-CR group patients. Dual hematologic and VEGF complete responses carry further benefit for survival (median TTNT, 129 months versus 68 months; P < .0001). Seven cases of second primary malignancy were recorded, all of which were solid tumors. Front-line ASCT resulted in excellent long-term survival in patients with POEMS syndrome, with the best survival observed in those achieving dual hematologic and VEGF CRs.

Primary Plasma Cell Leukaemia with Lambda Light Chain secretion and Chromosomal abnormalities presenting as hyperleukocytosis - A case report.

Primary plasma cell leukaemia (pPCL) is a rare and lethal form of plasma cell dyscrasia that can occur either de novo (primary) or as a leukemic transformation of refractory or relapsed multiple myeloma. We report a case of pPCL with lambda light chain disease and multiple chromosomal abnormalities in a 75-year-old female who presented with generalized weakness. Her peripheral blood smear showed hyperleukocytosis with 78% circulating plasma cells. Serum protein electrophoresis (SPE) does not reveal the M band and serum immunofixation (SI) light chain analysis in serum showed an elevated lambda light chain. Skeletal radiography and PET-CT (positron emission tomography—computerized tomography) did not reveal any lytic lesions. Immunophenotypic studies reveal a CD38-positive population with negativity for T cells, B cells, myeloid markers, and a negative CD45. Fluorescent in situ hybridization (FISH) analysis results disclosed the deletion of 13q14.3 and t(11; 14). This case highlighted the usefulness of the peripheral smear findings and high fluorescent lymphocyte activity, which directed the pathologist to initiate workup for pPCL, and comprehensive laboratory biochemical and radiological evaluation further helps to confirm and differentiate pPCL from multiple myeloma. Bangladesh Journal of Medical Science Vol. 22 No. 04 October’23 Page : 932-936

POEMS Syndrome-Clinical Picture and Management. Current Knowledge.

POEMS syndrome is a rare form of plasma cell dyscrasia. Difficulties arise already at the stage of making the diagnosis (complex and heterogeneous clinical picture) and continue during the course of treatment (lack of guidelines for therapy, data coming mainly from reports and short series of patients). In this article we review the current state of knowledge on POEMS syndrome diagnostics, clinical characteristics, prognosis, reported treatment outcomes and the emergence of the new therapeutic strategies.

MM-010 Spontaneous Prosthetic Fracture in a Patient With Relapsed Multiple Myeloma

Plasmacytomas are a form of plasma cell dyscrasia that present as a single mass of monoclonal plasma cells located either extramedullary or intraosseous. They can present as a solitary or multiple mass, either at diagnostic or in the context of a relapsed refractory patient. The latter scenario usually has a dismal prognosis. Bone fractures are frequent in patients with multiple myeloma (MM), sometimes requiring a surgical approach. Eventually, plasmacytomas can also develop surrounding a synthetic prothesis. Prosthetic fractures are a rare complication and usually present a challenging situation. To describe a case of prosthetic spontaneous fracture and exposure. Case report. A 52-year-old woman with a history of IgG kappa MM diagnosed in 2014 was admitted for severe back pain. Her MM was treated with CyBorD and consolidation with an autologous stem cell transplant. She also underwent surgery for a dorsal vertebral fracture at diagnosis. She had a first relapse in 2018 receiving a carfilzomib-based regimen as re-induction. In 2019 she had a 3° relapse with extensive bone disease and supraclavicular plasmacytoma in a lymph node. She received VTD-PACE for 3 cycles, achieving a partial response. At admission in 2020, dorsal x-ray showed prosthetic fracture. She also had a dorsal plasmacytoma. Her ECOG performance status was 4, and she received palliative care and a VAD regimen. The plasmacytoma continued to grow and ulcerated. Prothesis exposure was confirmed. Because of her bad performance status, she received palliative treatment. Extramedullary relapses of plasma cell dyscrasias are usually aggressive and have a dismal prognosis. Rare reports and recommendations are available in the literature regarding the treatment of prosthetic fractures, and there is currently no consensus about the standard management for these patients. We present this case because of the rare incidence of prosthetic fractures.

Case Report: A case of IgD lambda/lambda Multiple Myeloma in patient with acute renal failure and without monoclonal spike in serum electrophoresis

BackgroundIgD Multiple Myeloma is a rare form of plasma cell dyscrasia and accounts for approximately 1-2% of all cases of Multiple Myeloma. It mainly affects young, male subjects; it is characterized by an aggressive course, a high production of Bence Jones protein, acute renal failure and an often unfortunate outcome compared to the other isotypes of MM. A distinctive feature is the lack of a monoclonal peak on serum protein electrophoresis (SPE).Case reporta 57-year-old man with pain in his left lower limb and weight loss goes to the Emergency Department (Emergency Department). Laboratory tests performed showed normocytic normochromic anemia (Hemoglobin 9.4 g/dL), acute renal failure (s-creatinine 2.85 mg/dL, e-GFR 23 mL/min/1.73 m². serum protein electrophoresis (SPE) detected only mild polyclonal in the gamma zone with no evidence of any monoclonal peak.Resultsserum immunofixation (s-IFE) showed a monoclonal IgD λ band and a monoclonal λ band. The Free Light Chains (s-FLC) measurement showed a ratio of 0.04. The bone marrow biopsy confirmed an infiltration of&amp;gt; 20% of clonal plasma cells; renal biopsy diagnosed “cast nephropathy”.ConclusionIgD λ/λ Multiple Myeloma is a rare form of this disease with a poor prognosis; an early and correct laboratory diagnosis is crucial for appropriate treatment and effective monitoring in order to improve patient outcome.

BRAF V600E Positive Hairy Plasma Cell Leukemia; Are the Cytoplasmic Projections in Plasma Cells Predictive of a Particular Molecular Characterization?

Introduction: Plasma cell leukemia (PCL) is a rare and clinically aggressive form of plasma cell dyscrasia. Despite the significant role of BRAF mutation in plasma cell neoplasms, this mutation has been rarely considered in these cases. Finding evidence guiding us toward assessing the BRAF mutation in patients with plasma cell neoplasms could help make the suitable decision for targeted therapy. Case Presentation: A 79-year-old man presented with leukocytosis. Peripheral blood smear exhibited marked lymphocytosis and infiltration of about 50% abnormal lymphoid cells with slender cell-surface projections and oval shape nucleus. These findings raised the provisional diagnosis of hairy cell leukemia (HCL) or HCL variants (HCL-v). Molecular analysis confirmed the presence of BRAFV600E mutation, which was in agreement with HCL diagnosis, albeit the flow cytometric assessment of abnormal lymphocytes corroborated PCL. Conclusions: Together with the previous comprehensive analysis regarding the association of cytoplasmic projections and BRAF mutations, our findings could suggest this morphological characteristic in plasma cells (PCs) as an indication for the assessment of BRAF V600E mutation in PC dyscrasias.

Poster: MM-251: POEMS Syndrome: A Rare Form of Plasma Cell Dyscrasia Successfully Treated with Multiple Myeloma Protocol

Poster: MM-251: POEMS Syndrome: A Rare Form of Plasma Cell Dyscrasia Successfully Treated with Multiple Myeloma Protocol

MM-251: POEMS Syndrome: A Rare Form of Plasma Cell Dyscrasia Successfully Treated with Multiple Myeloma Protocol

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare multisystemic disease that occurs in the setting of a plasma cell dyscrasia. Unfortunately, there is no standard treatment for this disorder. We report the case of a 50-year-old male patient, previously healthy, who was referred to my clinic. The patient was in a wheelchair for eight months, with a history of peripheral neuropathy that worsened over the last two weeks, associated with a monoclonal gammopathy (IgG lambda=5.4 g/L). He had an electromyogram documenting a demyelinating axonal polyneuropathy predominating in both lower limbs. The auto-immune serology workup was negative. Cerebrospinal fluid studies revealed albuminorrhachia with a negative paraneoplastic profile. He was suspected of having immune demyelinating polyneuropathy and received intravenous immunoglobulins without improvement. Consequently, a complete workup in the hematology department lead to the diagnosis of POEMS syndrome after fulfilling the following major and minor criteria: polyneuropathy; monoclonal gammopathy; mixed lytic/sclerotic hypermetabolic bone lesions, one of which revealed plasma cells on biopsy (monotypic immunoglobulin light chain lambda); no increase in bone marrow plasma cells; elevated VEGF level >5000 pg/mL (normal value

Plasma Cell Leukemia (PCL): Clinical Characteristics, Outcomes, and the Impact of Circulating Plasma Cells (CPC) Percentage — A Single Center Experience

Introduction: PCL is a rare, highly proliferative form of plasma cell dyscrasia with poor clinical outcomes. The current criteria for diagnosis requires ≥20% CPCs and/or absolute CPC count of ≥2 x109/L. Recently, the prognostic impact of CPCs below this threshold has been explored. Herein we report a single center experience of PCL, analyzing patients with primary PCL (pPCL), secondary PCL (sPCL), and those with various percentages of CPCs not meeting the current diagnostic criteria.Methods: Patients treated between 2004-2017 with CPCs detected via a manual differential and/or flow cytometry were identified. Based on percentage of peripheral blood PCs, patients were stratified into three groups: 1-4% CPCs, 5-19% CPCs, and ≥20% CPCs. These groups were further divided into pPCL or sPCL, defined as CPCs present with de novo disease versus CPCs measured in the setting of relapsed/refractory myeloma, and spillover CPCs (fulfilling neither of the former categories). Clinical features, treatment responses, and survival outcomes were compared between the three groups. Continuous variables were compared using t-test; categorical variables were compared using Fisher's exact test. Overall survival (OS) was estimated by the Kaplan-Meier method. Risk factors for OS were assessed by Cox regression model.Results: A total of 91 patients with CPCs were identified as Group 1: CPCs ≥20% in 45 (49%), Group 2: CPCs ≥ 5-19% in 11 (12%), and Group 3, CPCs ≤4% in 35 (38%). pPCL in 26 (29%), sPCL in 35 (38%), and spillover in 30 (33%). Patient characteristics at time CPCs were first identified are shown in the Table below. Median age was 56 years (25-84), 57% were female. Sixty six patients (73%) had high-risk cytogenetics, most common abnormalities were hypodiploidy, gain of 1q, and del 17p. There was no difference in treatment response or OS among different groups, suggesting factors other than cytogenetics may be critical in the pathogenesis of PCL. Forty four patients (48%) had extramedullary disease (EMD), of which 6 had CNS involvement. CD56 expression data was available for 68 patients, 30 had positive PC expression of CD56, of which 20 (67%) had EMD, p=0.09 is of marginal statistical significance. Immunomodulatory agents (IMiD) and proteasome inhibitors (PI) were the main treatments used in > 75% of the patients; 26% received combination of IMiD and PI with cytotoxic chemotherapy (VTD-PACE). Approximately half of the patients (48%) had an autologous SCT and 4.4% (n=4) underwent allogeneic SCT. Median OS for the whole group was 8.5 months (95% CI: 0.4-32.0). Group 1 had a median OS of 9.7 months (CI: 5.4-13.4), Group 2 had median OS of 2.6 months (CI: 0.4-NR), and Group 3 had median OS of 13.4 months (CI: 7.4-32.0). Univariable Cox regression model revealed that sPCL had a poor OS compared with pPCL (p=0.01) and spillover group (p=0.004). Inferior survival was noted for patients with low platelets (p=0.0002), high LDH (p=0.003), advanced ISS (p=0.006) and possibly in those with EMD (p=0.06). Treatment regimen had no impact on OS; VTD-PACE, the most commonly used regimen in pPCL had no impact on OS, probably reflecting the aggressive biology of the disease rather than effectiveness of any particular regimen.Conclusions: Despite improvement in outcomes for MM, PCL patients continue to do poorly. Patients with ≥5% CPCs have similar clinical presentation and overall poor outcomes when compared to the historically defined PCL patients with ≥20% CPCs, supporting the recent recommendations to redefine PCL. Low platelet counts and high LDH are the most significant predictors of OS. Further studies with this expanded PCL patient population are warranted to better understand the significant drivers of disease, and lead to new innovative treatment approaches. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Solitary plasmacytoma in the calcaneus: A case report

Solitary plasmacytoma is a rare form of plasma cell dyscrasia. The purpose of this article is to present a case of solitary plasmacytoma involving the calcaneus, and only a few cases involving the same site have been published. The case is clinically presented with swelling and localized pain, which was initially treated as cellulitis. Image studies of X-ray, bone scan, and computed tomography found osteolytic lesions over the calcaneus. Operative tumor excision was done. The result of pathology was solitary plasmacytoma and then the patient received adequate therapeutic treatment.

Serum Hevylite® assay in the differential diagnosis of patients with high suspicion of AL Amyloidosis.

AL amyloidosis (AL) is a malignant form of plasma cell dyscrasia (PCD). It is insidious, and its end-organ damage can mimic that of common diseases. At diagnosis, routine tests for monoclonal protein are insufficient for the differential diagnosis. We hypothesized that Hevylite® (HLC) isotype patterns may help discriminate between AL and benign PCD states. Serum samples of patients with a high clinical suspicion of AL were prospectively tested for IgGκ, IgGλ, IgAκ, IgAλ, IgMκ, and IgMλ concentrations and ratios using Hevylite® assays in a blinded manner. The results were correlated with the final diagnosis. Of the 99 samples analyzed, 46 were newly diagnosed AL, and the majority, 38 (82.6%), presented with suppression of at least one HLC isotype. Of the 53 benign PCD patients, 36 (67.9%) presented with elevation of at least one HLC isotype. By multivariate analysis, Hevylite® was the best independent test predictor of AL amyloidosis. HLC suppression had an odds ratio (OR) of 14.591, and elevation an OR of 10.149, and thus were significant variables in the diagnosis and exclusion of AL. Furthermore, patients with both HLC suppression, together with no elevation, had an OR of 316.69 to be diagnosed with AL rather than a benign PCD. Hevylite® HLC analysis for Ig isotypes patterns offers an effective non-invasive tool in the evaluation of patients with high suspicion of AL and may assist further explorative decisions for diagnosis.

Combining TEMPI syndrome with hereditary thrombophilia

At the present time, there is a lot of information about clonal plasma cell processes, def ned as the plasma cell dyscrasi а s. We present a case of TEMPI syndrome, which was f rst detected in Russia and belongs to a rare form of plasma cell dyscrasia, with a description of the clinical symptoms, difficulties in differential diagnosis in the patient, and the genetic form of thrombophilia detected in this syndrome. The main manifestations of TEMPI syndrome are telangiectasias, erythrocytosis, monoclonal gammapathy, perinephric f uid collections, and intrapulmonary shunting. Currently, the mechanisms of the systemic effect of monoclonal secretion in this form of plasma cell dyscrasia have not yet been clearly established, and moreover, therapeutic approaches to its treatment have not been developed. The use of bortezomib in the onset of the disease and, further, as part of rotating courses with dexamethasone and cyclophosphane, gave a clinical and hematological effect.

Successful treatment with bortezomib-containing regimen of primary plasma cell leukemia: a case report

Plasma cell leukemia represents the most aggressive form of plasma cell dyscrasia. We report a 67-year old male with no previous medical illnesses presented with anemic symptoms. Blood film revealed 35% circulating plasma cells, bone marrow biopsy showed plasma cells constituting 85%. Diagnosis of primary plasma cell leukemia was completed. Induction chemotherapy with bortezomib, doxorubicin, and dexamethasone was started. After the first cycle, plasma cells in peripheral blood disappeared. The patient had complete remission at evaluation after the third cycle. Re-evaluation after the sixth cycle showed that he maintained remission. As he was non-transplant eligible, he was we kept on maintenance bortezomib. Twenty-four months after the diagnosis, the patient remains in remission.

PRIMARY PLASMA CELL LEUKEMIA: A RARE CASE REPORT

Plasma cell leukemia (PCL) is a rare form of plasma cell dyscrasia. Between 2% and 4% of malignant PCD cases are PCL. The presentation may be primary, de novo, or secondary, evolving from an existing case of myeloma as part of the terminal phase of the disease. The median age of patients is 50-60 years with an equal incidence in males and females. Here, we report a case of primary PCL, presenting at the age of 62 years.

Solitary Intracranial Plasmacytoma in an Unusual Location – A Case Report

Plasmacytoma is rare form of plasma cell dyscrasias, where there is malignant proliferation of plasma cells. Solitary plasmacytoma developsin isolation without systemic manifestations of multiple myeloma (MM). We report a case of cerebellopontine angle (CPA) plasma cytoma, which masqueraded as a schwannoma with multiple cranial nerve involvement and review a literature pertaining to the same pathological entity.

Primary solitary plasmacytoma of the liver \u2013 successful treatment with fractionated stereotactic radiotherapy (Cyberknife\xae): a case report

BackgroundSolitary plasmacytoma of the liver is a very rare and aggressive form of plasma cell dyscrasia. To the best of our knowledge, very few cases have been reported without systemic disease. We reported a rare case of hepatic solitary plasmacytoma that successfully responded to fractionated stereotactic radiotherapy.Case presentationA 64-year-old white French man had monoclonal gammopathy of the immune globulin G lambda type; he developed a cholestasis and cytolysis with the discovery of a subscapular nodule. A biopsy showed plasma cells and, for several reasons, the decision was made to use the fractionated stereotactic radiotherapy strategy. After 20 months, he is asymptomatic and the immune globulin G component has completely disappeared.ConclusionWe suggest considering Cyberknife® radiosurgery as an option for the treatment of hepatic solitary plasmacytoma.

Monoclonal gammopathy of undeterminated significance and endoneurial IgG deposition

Background:Monoclonal gammopathy of undeterminated significance is the most common form of plasma cell dyscrasia, usually considered as benign. In rare cases it may have a malignant course, sometimes limited to an organ such as peripheral nerves.Methods:We describe clinical, electrophysiological and pathological findings in a patient presenting a immunoglobulin G (IgG) paraproteinemic polyneuropathy clinically mimicking a chronic inflammatory demyelinating polyneuropathy.Results:Immuno-electron microscopy (immune-EM) demonstrated that the widenings of the myelin lamellae resulted from the infiltration of IgG between a significant number of myelin lamellae (with absence of inflammatory cells in the epineurium, endoneurium, and perineurium, and the lack signs of vasculitis). This patient was finally treated successfully with lenalidomide then mycophenolate mofetil.Conclusions:In polyneuropathies associated to a monoclonal gammopathy, a nerve biopsy may clinch the diagnosis. Immuno-EM may be required to determine the role of the pathological immunoglobulin in the destruction of the peripheral nerve parenchyma. Diagnosis of such a direct involvement of peripheral nerve can endorse more aggressive treatment of real efficiency.