Incidence, presenting features and outcome of extramedullary disease in multiple myeloma: a longitudinal study on 1003 consecutive patients

Management of patients with difficult-to-treat multiple myeloma

Newer treatments for multiple myeloma (MM) have improved response rates and survival for many patients. However, MM remains challenging to treat due to the propensity for multiple relapses, cumulative and emergent toxicities from prior therapies and increasing genomic complexity that arises due to clonal evolution. In particular, patients with relapsed/refractory MM often require increased complexity of treatment, yet still experience poorer outcomes compared with patients who are newly diagnosed. Additionally, several patient subgroups, including those with extramedullary disease and patients who are frail and/or have multiple comorbidities, have an unfavorable prognosis and remain undertreated. This review (based on an Updates-in-Hematology session at the 25th European Hematology Association Annual Congress 2020) discusses the management of these difficult-to-treat patients with MM.

Defining the undetectable: The current landscape of minimal residual disease assessment in multiple myeloma and goals for future clarity

Multiple Myeloma, the second most prevalent hematologic malignancy, yet lacks an established curative therapy. However, overall response rate to modern four-drug regimens approaches 100%. Major efforts have thus focused on the measurement of minute quantities of residual disease (minimal residual disease or MRD) for prognostic metrics and therapeutic response evaluation. Currently, MRD is assessed by flow cytometry or by next generation sequencing to track tumor-specific immunoglobulin V(D)J rearrangements. These bone marrow-based methods can reach sensitivity thresholds of the identification of one neoplastic cell in 1,000,000 (10-6). New technologies are being developed to be used alone or in conjunction with established methods, including peripheral blood-based assays, mass spectrometry, and targeted imaging. Data is also building for MRD as a surrogate endpoint for overall survival. Here, we will address the currently utilized MRD assays, challenges in validation across labs and clinical trials, techniques in development, and future directions for successful clinical application of MRD in multiple myeloma.

Outside the box-Surgery for aggressive plasmacytoma in scar

This report introduces the concept of large-scale surgery and reconstruction when all other medical means of treatment have failed. In select cases, this may act as a mode of buying time and allowing the patient to receive second- or third-line treatments.

Extraosseous multiple myeloma: imaging spectrum in the abdomen and pelvis

Multiple myeloma represents a subset of plasma cell dyscrasias characterized by the proliferation of plasma cells typically in the bone marrow, representing approximately 1% of all cancers and 15% of hematologic malignancies. Often multiple myeloma is limited to the skeletal system; however, a small percentage (<5%) of patients will develop extraosseous manifestations. We review the current WHO classification of plasma cell dyscrasias and use multimodality imaging including US, CT, MRI, and PET-CT to illustrate the spectrum of extraosseous multiple myeloma in the abdomen and pelvis. Because extraosseous multiple myeloma is associated with a poorer prognosis and decreased survival, it is important for the radiologist to become familiar with a variety of extraosseous manifestations in the abdomen and pelvis, especially in a patient with a known diagnosis of multiple myeloma and the development of an abdominal or pelvic mass.

Game of Bones: How Myeloma Manipulates Its Microenvironment

Multiple myeloma is a clonal disease of long-lived plasma cells and is the second most common hematological cancer behind Non-Hodgkin’s Lymphoma. Malignant transformation of plasma cells imparts the ability to proliferate, causing harmful lesions in patients. In advanced stages myeloma cells become independent of their bone marrow microenvironment and form extramedullary disease. Plasma cells depend on a rich array of signals from neighboring cells within the bone marrow for survival which myeloma cells exploit for growth and proliferation. Recent evidence suggests, however, that both the myeloma cells and the microenvironment have undergone alterations as early as during precursor stages of the disease. There are no current therapies routinely used for treating myeloma in early stages, and while recent therapeutic efforts have improved patients’ median survival, most will eventually relapse. This is due to mutations in myeloma cells that not only allow them to utilize its bone marrow niche but also facilitate autocrine pro-survival signaling loops for further progression. This review will discuss the stages of myeloma cell progression and how myeloma cells progress within and outside of the bone marrow microenvironment.

Clinical Characteristics and Prognostic Analysis of Multiple Myeloma with Extramedullary Disease: A SEER-Based Study

Background

Extramedullary disease (EMD), an infrequent manifestation of multiple myeloma (MM), can present at diagnosis or develop during the disease course. EMD can be clinically divided into bone-related EMD (EMD-B) and soft tissue-related EMD (EMD-S). The purpose of our study is to investigate the clinical characteristics, survival outcomes, and prognostic factors of MM patients with EMD.

Methods

A total of 155 MM patients with EMD were ultimately enrolled in our study by retrieving the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan–Meier survival curves and log-rank test for overall survival (OS) and myeloma-specific survival (MSS) were conducted to compare each potential variable. Variables with a p value <0.1 in the univariate Cox regression were incorporated into the multivariate Cox model to determine the independent prognostic factors, with a hazard ratio (HR) >1 representing adverse prognostic factors.

Results

The median age at diagnosis was 63 years old. EMD-B occurred in 99 patients (63.90%), while EMD-S occurred in 56 cases (36.10%). Patients with EMD-S had a significant survival disadvantage in MSS (HR = 1.844, 95% CI 1.117–3.042, p = 0.017) and OS (HR = 1.853, 95% CI 1.166–2.942, p = 0.009) compared to those with EMD-B. Patients with EMD interval ≤24 months were at higher risk of death than those with EMD at diagnosis in MSS (HR = 1.885, 95% CI 1.175–3.346, p = 0.042) and in OS (HR = 1.33, 95% CI 1.119–2.529, p = 0.036). Patients with EMD interval >24 months were at a lower risk of death as opposed to those with EMD at diagnosis.

Conclusion

Age at MM diagnosis, site of EMD, and time interval from diagnosis to EMD occurrence were independent prognostic factors in MM patients with EMD. EMD-B bore a better prognosis than EMD-S.

[Clinical characteristics and outcomes of patients newly diagnosed with multiple myeloma with extramedullary disease]

目的

比较伴骨相关髓外（EM-B）和骨外髓外（EM-E）病变的初诊多发性骨髓瘤（NDMM）患者的临床特征及预后，并探讨影响预后的因素。

方法

回顾性分析2009年11月至2019年3月江苏省人民医院血液科诊治的80例伴髓外病变的NDMM患者的临床特征、预后及影响预后的因素。

结果

80例累及髓外的NDMM患者中伴EM-B者51例，伴EM-E者29例。与EM-B组相比，EM-E组β₂-微球蛋白水平（5.82 mg/L对3.99 mg/L，P＝0.030）、乳酸脱氢酶水平（256 U/L对184 U/L，P＝0.003）、1q21扩增发生率（78.6％对53.1％，P＝0.035）、肿瘤细胞Ki-67增殖指数（50％对25％，P＝0.002）升高，CD56阳性率（14.3％对66.7％，P＝0.057）和治疗总有效率（60.0％对82.3％，P＝0.034）降低。EM-E组和EM-B组的中位总生存（OS）时间分别为14.5、49.5个月，中位无进展生存（PFS）时间分别为9.0、18.0个月。与EM-B组患者相比，EM-E组患者的OS、PFS时间均明显缩短（P值分别为0.035和<0.001）。在接受蛋白酶体抑制剂诱导化疗的患者中，两组PFS时间的差异无统计学意义（P＝0.263）。Cox回归多因素分析显示：诱导治疗后最佳疗效未达部分缓解（PR）是EM-E组患者OS、PFS的独立不良预后因素（P值分别为0.031、0.005）；ISS-Ⅲ期、诱导治疗后最佳疗效未达PR为EM-B组患者OS的独立不良预后因素（P值分别为0.009、0.044）。

结论

伴EM-E的NDMM患者与伴EM-B的患者有不同的临床特征及预后，前者的预后明显较后者差，蛋白酶体抑制剂可改善EM-E组患者的PFS。

Effect of the ABO blood groups on the development, clinical features and survival of multiple myeloma

Background

Multiple myeloma (MM) is a cytogenetically heterogeneous and incurable plasma cell disease with unknown etiology. It is thought that the ABO blood groups may play a role in the etiology of many diseases. The purpose of this study is to determine whether there is a relationship between the ABO blood groups and the development of MM, clinical findings and overall survival.

Methods

In this single-center, retrospective and observational study, 198 patients with known blood types who diagnosed with MM between January 2012 and June 2020 were included.

Results

It was shown that individuals with blood group 0 had a significantly lower risk of MM (OR = 0.575, 95% confidence interval 0.416-0.794, P = 0.001). The incidence of extramedullary lesion was significantly higher in those with 0 blood group compared to other blood groups (P = 0.000). Overall survival was significantly shorter in patients with 0 blood group than those without 0 blood group (P = 0.007).

Conclusion

Individuals with 0 blood group had a lower risk of developing MM. It was determined that having 0 blood group is a predisposing factor for the development of extramedullary lesion in MM patients. However, it was shown that having a blood group of 0 was a very significant prognostic factor for MM patients and was associated with short OS.

Extramedullary Disease in Multiple Myeloma

PURPOSE OF REVIEW

Extramedullary disease (EMD) is a rare but recognized manifestation of multiple myeloma (MM), characterized by involvement of several organs including skin, liver, lymphatic system, pleura, and central nervous system. The incidence is about 3-5% in newly diagnosed MM patients, but has been reported in up to 20% patients in the relapsed MM setting.

RECENT FINDINGS

Presence of EMD has been associated with more aggressive phenotype of MM, elevated serum lactate dehydrogenase (LDH) enzyme, and high-risk cytogenetics [deletion 17p, translocation (4;14), translocation (14;16)]. There are several hypotheses of how EMD occurs, including factors leading to bone marrow emancipation and hematogenous spread. The treatment schema usually follows that of high-risk MM. The current review summarizes the disease characterization data, along with available data on clinical activity of available anti-MM agents for this entity.

Defining and Managing High-Risk Multiple Myeloma: Current Concepts

Multiple myeloma is a very heterogeneous disease. Despite advances in diagnostics and therapeutics, a subset of patients still experiences abbreviated responses to therapy, frequent relapses, and short survival and is considered to have high-risk multiple myeloma (HRMM). Stage III diagnosis according to the International Staging System; the presence of del(17p), t(4;14), or t(14;16) by fluorescence in situ hybridization; certain gene expression patterns; high serum lactic dehydrogenase level; and the presence of extramedullary disease at diagnosis are all considered indicators of HRMM. More recent evidence shows that patients who experience response to therapy but with a high burden of measurable residual disease or persistence of abnormal FDG uptake on PET/CT scan after initial therapy also have unfavorable outcomes, shaping the concept of dynamic risk assessment. Triplet therapy with proteasome inhibitors, immunomodulatory agents, and corticosteroids and autologous hematopoietic cell transplantation remain the pillars of HRMM therapy. Recent evidence indicates a benefit of immunotherapy with anti-CD38 monoclonal antibodies in HRMM. Future trials will inform the impact of novel immunotherapeutic approaches, including T-cell engagers, CAR T cells, and nonimmunotherapeutic approaches in HRMM. Those agents are likely to be deployed early in the disease course in the setting of risk- and response-adapted trials.

Characterising spatial heterogeneity of multiple myeloma in high resolution by whole body magnetic resonance imaging: Towards macro-phenotype driven patient management

Diagnosis of patients suspected of multiple myeloma requires a combination of serological and biochemical tests, bone marrow aspirate (BMA) and/or bone marrow trephine (BMT) biopsies as well as complementary information provided by whole-body cross-sectional imaging studies. However, given the heterogeneous nature of multiple myeloma, discrepancies can arise between disease burden on trephine and extent of disease within the marrow on whole-body magnetic resonance imaging (WB-MRI). Here, for the first time, we report on a series of symptomatic multiple myeloma patients for whom there was substantial discordance between disease burden on trephine and WB-MRI.

Multiple myeloma presenting as an intramedullary spinal cord tumor: a case report and review of the literature

Background

Extramedullary disease in multiple myeloma often portends a worse diagnosis. In approximately 1% of cases, multiple myeloma may metastasize to the central nervous system as either leptomeningeal involvement or an intracranial, intraparenchymal lesion. Spinal cord metastases, however, are exceedingly rare. We present a case of spinal cord multiple myeloma as well as a literature review of reported cases.

Case presentation

A 66-year-old African American man with multiple myeloma presented with acute midthoracic pain and lower extremity paresis and paresthesia. Magnetic resonance imaging of the spine revealed two contrast-enhancing intramedullary enhancing lesions in the T1–T2 and T6–T7 cord. Resection with biopsy yielded a diagnosis of metastatic multiple myeloma.

Conclusion

To date, only six cases of extramedullary disease to the spinal cord in patients with multiple myeloma have been reported, including our patient’s case. In all cases, neurologic deficit was observed at presentation, and magnetic resonance imaging of the spine revealed an intramedullary, homogeneously enhancing lesion. Current evidence suggests worse prognosis in patients with extramedullary disease to the central nervous system, and treatment paradigms remain debatable.

Genetic Basis of Extramedullary Plasmablastic Transformation of Multiple Myeloma

In patients with multiple myeloma, plasmablastic transformation in the bone marrow is rare and associated with poor outcomes. The significance of discordant extramedullary plasmablastic transformation in patients with small, mature clonal plasma cells in the bone marrow has not been well studied. Here, we report the clinicopathologic, cytogenetic, and molecular features of 10 such patients (male/female: 6/4, median age: 65 y, range: 48 to 76 y) with an established diagnosis of multiple myeloma in the bone marrow composed of small, mature plasma cells in parallel with a concurrent or subsequent extramedullary plasmablastic transformation. Eight patients with available survival data showed an overall aggressive clinical course with a median survival of 4.5 months after the diagnosis of extramedullary plasmablastic transformation, despite aggressive treatment and even in patients with low-level bone marrow involvement. Pathologically, the extramedullary plasmablastic myeloma were clonally related to the corresponding bone marrow plasma cells, showed high levels of CMYC and/or P53 expression with a high Ki-67 proliferation index by immunohistochemistry and harbored more complex genomic aberrations including frequent mutations in the RAS pathway and MYC rearrangements compared with their bone marrow counterparts. In summary, although genetic and immunohistochemical studies were not uniformly performed on all cases due to the retrospective nature of this study, our data suggest that discordant extramedullary plasmablastic transformation of multiple myeloma has an aggressive clinical course and is characterized by frequent mutations in the RAS pathway and more complex genomic abnormalities.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

Young age and autologous stem cell transplantation are associated with improved survival in newly diagnosed multiple myeloma

Background

Multiple myeloma is a disease of the elderly. However, 40% of patients are diagnosed before 65 years old. Outcomes regarding age as a prognostic factor in MM are heterogeneous.

Method

We retrospectively analyzed clinical characteristics, response to treatment and survival of 282 patients with active newly-diagnosed multiple myeloma, comparing results between patients younger and older than 65 years.

Main results

The frequency of multiple myeloma in those younger than 66 years was 53.2%. Younger patients presented with a more aggressive disease, more advanced Durie-Salmon stage (85.3% vs 73.5%; p = 0.013), extramedullary disease (12.7% vs 0%; p < 0.001), osteolytic lesions (78.7% vs 57.6%; p < 0.001) and bone plasmacytoma (25.3% vs 11.4%; p = 0.003). In spite of this, the overall response rate was similar between groups (80.6% vs 81.4%; p = 0.866). The overall survival was significantly longer in young patients (median, 65 months vs 41 months; p = 0.001) and higher in those who received autologous hematopoietic stem cell transplantation. The main cause of death was disease progression in both groups. Multivariable analysis revealed that creatinine ≥2 mg/dl, extramedullary disease, ≤very good partial remission and non-autologous hematopoietic stem cell transplantation are independent risk factors for shorter survival.

Conclusion

Although multiple myeloma patients younger than 66 years of age have an aggressive presentation, this did not translate into an inferior overall survival, particularly in those undergoing autologous hematopoietic stem cell transplantation.

Evaluating Daratumumab in the Treatment of Multiple Myeloma: Safety, Efficacy and Place in Therapy

Despite the tremendous advances in the treatment of multiple myeloma, mortality remains significant, highlighting the need for new effective strategies. In recent years, daratumumab, a novel human monoclonal antibody, binding CD38, has dramatically improved outcomes either as monotherapy or in combination with traditional regimens. Originally approved for relapsed/refractory multiple myeloma, this breakthrough medication is now being used as frontline therapy in patients with newly diagnosed multiple myeloma regardless of transplant eligibility, with trials showing promising results. Its tolerable side-effect profile and enhanced efficacy have led to its widespread incorporation into the management of multiple myeloma and further exploration about its use in other entities such as smoldering myeloma, MGUS, MGRS and amyloidosis. This comprehensive review will discuss daratumumab's mechanism of action and safety profile, as well as research which has defined its current approved indications, and ongoing clinical investigation that will define its future.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in newly diagnosed multiple myeloma: a systematic review and meta-analysis

OBJECTIVES

We performed a systematic review and meta-analysis on the prognostic values of ¹⁸F-FDG PET/CT in patients with newly diagnosed multiple myeloma (MM).

METHODS

PubMed and Embase were searched until July 10, 2019, for studies that reported the prognostic significance of ¹⁸F-FDG PET in patients with newly diagnosed MM, with overall (OS) and progression-free survival (PFS) included as outcomes. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were meta-analytically pooled using a random-effects model.

RESULTS

Fifteen studies (1670 patients) were included for qualitative synthesis. Among multiple PET parameters, the presence of extramedullary disease (EMD), more than three focal lesions (FLs), and high FDG uptake were widely evaluated and significantly associated with shorter OS and PFS in most of the included studies. Among 11 studies included in quantitative synthesis, the overall HRs of EMD, more than three FLs, and high FDG uptake on PFS were 2.12 (95% CI, 1.52-2.96), 2.38 (95% CI, 1.84-3.07), and 2.02 (95% CI, 1.51-2.68), respectively. The pooled HRs of those three parameters on OS were 2.37 (95% CI, 1.77-3.16), 3.29 (95% CI, 2.38-4.56), and 2.28 (95% CI, 1.67-3.13). No statistical differences were found across parameters for either PFS (p = 0.6822) or OS (p = 0.2147).

CONCLUSIONS

Pretreatment ¹⁸F-FDG PET/CT is a significant predictor for disease progression and survival in patients with MM. It may be a useful prognostic biomarker capable of accurate risk stratification and application in clinical decision-making for newly diagnosed MM.

KEY POINTS

• There remain unmet clinical needs for reliable prognostic biomarkers in patients with newly diagnosed multiple myeloma. • This meta-analysis shows that the presence of extramedullary disease, more than three focal lesions, and high FDG uptake from baseline ¹⁸F-FDG PET are significant prognostic factors. • These imaging biomarkers might help the accurate stratification of patient prognosis which is required for choosing an appropriate therapeutic strategy in clinical practice.

A Rare Case of Extramedullary Plasmacytoma Presenting as Large Abdominal Mass

A 79-year-old female with a past medical history of multiple myeloma, diabetes mellitus and chronic kidney disease presented to the hospital with generalized weakness. The patient was found to have a firm abdominal wall mass with no underlying skin changes or drainage on physical examination. Computerized tomography of the abdomen and pelvis without contrast revealed a large mass-like structure in the anterior abdominal wall in the subcutaneous region extending into the abdomen through the mesentery with juxtaposition and partial involvement of the left hepatic lobe and distal stomach. Solitary extramedullary plasmacytomas are extremely rare tumors that occur outside of the bone marrow in the absence of systemic involvement. This case reports details the finding of an extramedullary plasmacytomas, which accounts for less than 5% of plasma cell neoplasms.

Management of central nervous system involvement in multiple myeloma after autologous hematopoietic stem cell transplantation

Multiple myeloma (MM) is characterized by uncontrolled clonal proliferation of plasma cells, mainly in bone marrow, and its extramedullary involvement is rare. Central nervous system involvement in MM is a highly aggressive disease with a survival of less than 6 months. The best treatment regimen for MM with CNS involvement is still unknown and in most patients, the prognosis is unfavorable. To date, there is no report of CNS involvement without evidence of systemic involvement in a known case with MM. Here, we report a 58-year-old male with MM who recurred CNS involvement without evidence of systemic involvement following autologous stem cell transplant.

Minimal Residual Disease in Multiple Myeloma: Current Landscape and Future Applications With Immunotherapeutic Approaches

The basic principle that deeper therapeutic responses lead to better clinical outcomes in cancer has emerged technologies capable of detecting rare residual tumor cells. The need for ultra-sensitive approaches for minimal residual disease (MRD) detection is particularly evident in Multiple Myeloma (MM), where patients will ultimately relapse despite the achievement of complete remission, which is commonplace due to remarkable therapeutic advances. Consequently, current response criteria on MM have been amended based on MRD status and MRD negativity is now considered the most dominant prognostic factor and the most valuable indicator for a subsequent relapse. However, there are particular limitations and several aspects for MRD assessment that remain open. This review summarizes current data on MRD in the clinical management of MM, highlights open issues and discusses the challenges and the endless opportunities arising for both patients and clinicians. Furthermore, it focuses on the current status of MRD in clinical trials, its dynamics in addressing debatable aspects in the clinical handling and its potential role as the prevailing factor for future MRD-driven tailored therapies.

Can 18F-NaF PET/CT before Autologous Stem Cell Transplantation Predict Survival in Multiple Myeloma?

There is an unmet need for positron emission tomography (PET) radiotracers that can image bone disease in multiple myeloma (MM) in a more sensitive and specific way than the widely used ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). Sodium fluoride (¹⁸F-NaF) is a highly sensitive tracer of bone reconstruction, evolving as an important imaging agent for the assessment of malignant bone diseases. We attempted to investigate for the first time the prognostic significance of ¹⁸F-NaF PET/CT in newly diagnosed, symptomatic MM patients planned for autologous stem cell transplantation (ASCT). Forty-seven patients underwent dynamic and static PET/CT with ¹⁸F-NaF before treatment. After correlation with the respective findings on CT and ¹⁸F-FDG PET/CT that served as reference, the ¹⁸F-NaF PET findings were compared with established factors of high-risk disease, like cytogenetic abnormalities as well as bone marrow plasma cell infiltration rate. Furthermore, the impact of ¹⁸F-NaF PET/CT on progression-free survival (PFS) was analyzed. Correlation analysis revealed a moderate, significant correlation of the ¹⁸F-NaF parameters SUV_average and K₁ in reference tissue with bone marrow plasma cell infiltration rate. However, no significant correlation was observed regarding all other ¹⁸F-NaF PET parameters. Survival analysis revealed that patients with a pathologic ¹⁸F-NaF PET/CT have a shorter PFS (median = 36.2 months) than those with a physiologic scan (median = 55.6 months) (p = 0.02). Nevertheless, no quantitative ¹⁸F-NaF parameter could be shown to adversely affect PFS. In contrast, the respective analysis for quantitative dynamic ¹⁸F-FDG PET/CT revealed that the parameters SUV_max, fractional blood volume (V_B), k₃ and influx from reference tissue as well as SUV_average from MM lesions had a significant negative impact on patient survival. The herein presented findings highlight the rather limited role of ¹⁸F-NaF PET/CT as a single PET approach in MM.

Multiple myeloma with central nervous system relapse

Central nervous system involvement in multiple myeloma is a rare complication but carries a very poor prognosis. We provide a review of current literature, including presentation, treatment and survival data, and describe our experience in a regional hematologic malignancy diagnosis center where, over a 15-year period, ten cases were identified. Although the median age of onset, frequently between 50-60 years, is comparatively young, those diagnosed usually have a preceding diagnosis of multiple myeloma and often have had several lines of treatment. We discuss putative underlying factors such as prior treatment and associations including possible risk factors and features suggestive of a distinct biology. Central nervous system involvement may be challenging to diagnose in myeloma, displaying heterogeneous symptoms that can be confounded by neurological symptoms caused by the typical features of myeloma or treatment side-effects. We discuss the clinical features, imaging and laboratory methods used in diagnosis, and highlight the importance of considering this rare complication when neurological symptoms occur at presentation or, more commonly, during the disease pathway. In the absence of clinical trial data to inform an evidence-based approach to treatment, we discuss current and novel treatment options. Finally, we propose the establishment of an International Registry of such cases as the best way to collect and subsequently disseminate presentation, diagnostic and treatment outcome data on this rare complication of multiple myeloma.

Carfilzomib Based Treatment Strategies in the Management of Relapsed/Refractory Multiple Myeloma with Extramedullary Disease

Published experience with carfilzomib in patients with relapsed/refractory multiple myeloma (RRMM) and extramedullary disease (EMD) is still limited. The current study aimed to assess the efficacy and safety of carfilzomib containing therapy regimens in EMD. We retrospectively analyzed 45 patients with extramedullary RRMM treated with carfilzomib from June 2013 to September 2019. The median age at the start of carfilzomib was 64 (range 40-80) years. Twenty (44%) and 25 (56%) patients had paraosseous manifestation and EMD without adjacency to bone, respectively. The serological overall response rate (ORR) was 59%. Extramedullary response was evaluable in 33 patients, nine (27%) of them achieved partial remission (PR) (ORR = 27%). In 15 (33%) patients, we observed no extramedullary response despite serological response. The median progression-free survival (PFS) and overall survival (OS) were five (95% CI, 3.5-6.5) and ten (95% CI, 7.5-12.5) months, respectively. EMD without adjacency to bone was associated with a significantly inferior PFS (p = 0.004) and OS (p = 0.04) compared to paraosseous lesions. Carfilzomib based treatment strategies showed some efficacy in heavily pretreated patients with extramedullary RRMM but could not overcome the negative prognostic value of EMD. Due to the discrepancy between serological and extramedullary response, evaluation of extramedullary response using imaging is mandatory in these patients.

Plasmacytoma in patients with multiple myeloma: morphology and immunohistochemistry

BACKGROUND

To study the histological structure and immunohistochemical (IHC) parameters of the plasmacytoma tumour substrate in patients with multiple myeloma (MM).

METHODS

The study included 21 patients (10 men/11 women) aged 23 to 73 years old with newly diagnosed MM complicated by plasmacytoma. Bone plasmacytoma was diagnosed in 14 patients, and extramedullary plasmacytoma was diagnosed in 7 patients. Plasmacytoma tissue specimens were examined using a LEICA DM4000B microscope. Anti-CD56, anti-CD166, anti-CXCR4, anti-Ki-67, and anti-c-MYC antibodies were used for IHC study of plasmacytoma biopsies.

RESULTS

When comparing the morphology of bone and extramedullary plasmacytoma, no significant differences were revealed; however, the substrate of extramedullary plasmacytoma was more often represented by tumour cells with an immature morphology than was the bone plasmacytoma substrate (57.1% vs. 28.6%, respectively). We revealed a significant difference in the expression of CD166 between bone and extramedullary plasmacytoma. The mean values ​​of CD166 expression in bone plasmacytoma cells were significantly higher (36.29 ± 7.61% versus 9.57 ± 8.46%, respectively; p = 0.033) than those in extramedullary plasmacytoma cells. We noticed that in extramedullary plasmacytoma cells, there were higher values for the Ki-67 index than in bone plasmacytoma cells, and this result was independent of cell morphology.

CONCLUSION

The mechanisms involved in the dissemination of tumour plasma cells are currently unexplored. Even in such a small sample, some differences in expression could be identified, which may indicate that different mechanisms lead to the formation of bone and extramedullary plasmacytomas. Specifically, the expression of CD166 in extramedullary plasmacytoma cells was almost 4 times lower than that in bone plasmacytoma cells, which may indicate the involvement of CD166 in the mechanisms of bone destruction. The proliferative activity of extramedullary plasmacytoma cells was shown to be higher than that of bone plasmacytoma cells.

Orbital Plasmacytoma, An Uncommon Presentation of Advanced Multiple Myeloma

Introduction

Extramedullary plasmacytomas are present in 13% of multiple myeloma (MM) patients. Less than 5% of MM cases are non-secretory. The orbital location is uncommon and a minority of orbital tumours are plasmacytomas.

Description

The patient was a 71-year-old man, with right proptosis, retro-ocular pain and epistaxis with visual acuity 2/10, limitation of upper eye movement and scattered ecchymosis. Blood tests revealed severe anaemia, coagulopathy, increased serum creatinine, LDH and C-RP without improvement after antimicrobial treatment. Peripheral immunophenotyping showed 9.4% of plasma cells with intracytoplasmic clonal κ chains. IgG and λ chains were decreased with normal plasma and urine immunofixation. Orbital CT: retro-orbital superomedial tumour with bone destruction. Histology of the tumour and bone biopsy was consistent with plasmacytoma. The patient was deceased in 2 weeks.

Discussion

MM accounts for 10% of haematopoietic tumours; 7% of cases present with plasmacytomas at diagnosis. Orbital locations are rarely reported (frequently in the temporal region). Proptosis, ptosis and reduced visual acuity are common symptoms. However, orbital pain is less frequent. Most cases of MM demonstrate hypergammaglobulinaemia. Only 5% of MM cases are non-secretory.

The uncommon location, topography, symptom peculiarities and absence of monoclonality led to the diagnostic challenge of this fatal case of MM.

LEARNING POINTS

Extramedullary multiple myeloma with central nervous system and multiorgan involvement: Case report and literature review

Multiple myeloma is a hematologic malignancy due to monoclonal plasma cell proliferation. It is usually confined to the bone marrow, although extramedullary involvement is known to occur in almost any organ system; myelomatous spread to the central nervous system is a rare manifestation of myeloma. Extramedullary disease is thought to be related to hematogenous spread when myeloma cells show decreased cell surface receptor expression, allowing cells to escape from the bone marrow. Disease outside of the bone marrow generally indicates a poor prognosis; central nervous system involvement is associated with a median prognosis of less than 6 months, thereby requiring more aggressive treatment paradigms. We herein describe an unusual case of a patient with extramedullary multiple myeloma with central nervous system and multiorgan involvement. Despite an aggressive treatment strategy, the patient died a few months later after the initial diagnosis. The etiology, diagnostic criteria, clinical presentation, radiological features and differential diagnosis of this patient with extramedullary multiple myeloma are discussed here. The current treatment strategies are also briefly discussed.

Aggressive Central Nervous System Relapse after Autologous Stem Cell Transplant in Multiple Myeloma: Case Reports and Literature Review

Extramedullary disease is an aggressive presentation at diagnosis and relapse for multiple myeloma (MM) patients. Central nervous system (CNS) is a very rare manifestation of the extramedullary disease, accounting for less than 1% of MM on diagnosis and relapse. Neurological symptoms are unspecific and usually attributed to other causes. We present two patients with CNS-MM at relapse after autologous stem cell transplant highlighting the importance of clinical suspicion and interdisciplinarity at diagnostic workup as well as the need for intensive therapeutic options on such rare and aggressive cases. The presence of neurological abnormalities in anamnesis and physical examination on a patient with MM should always prompt to suspect of a CNS involvement, and active investigation must be undertaken. MRI is the standard radiological method to detect CNS-MM, with histopathological corroboration by stereotactic biopsy and CSF evaluation alongside. Treatment of CNS-MM should include two essential approaches—be able to cross the BBB and treat the systemic disease. There is no standard therapy for this extramedullary relapse, and a tailored and multiple therapy should be promptly started—intrathecal therapy, radiotherapy, and systemic therapy, including an immunomodulator.

Correlation Between Uptake of 18F-FDG During PET/CT and Ki-67 Expression in Patients Newly Diagnosed With Multiple Myeloma Having Extramedullary Involvement

The aim of this study was to evaluate the relationship of prognosis of patients with multiple myeloma having extramedullary involvement (EMM) with the ¹⁸F- fluorodeoxyglucose(18F-FDG) maximum standardized uptake value and the expression of Ki-67 in biopsy samples. Sixty-five patients were newly diagnosed with multiple myeloma presenting with EMM at our hospital from January 2005 to January 2015. Of these 65 patients, 20 were enrolled in this study. Over the last decade, both the maximum standardized uptake value and Ki-67 expression in these extramedullary lesions significantly correlated with progression-free survival, respectively (P= .039, P =.009). After combining—the maximum standardized uptake value and the Ki-67 expression as an integral—there was a significant correlation between both the overall survival (P = .027) and progression-free survival (P= .014). Patients have poor outcomes when EMM is detected at presentation. Both the maximum standardized uptake value and Ki-67 expression could aid in accurately evaluating EMM patient prognosis.

Evaluation of the Survival Outcomes of Multiple Myeloma Patients According to Their Plasmacytoma Presentation at Diagnosis

Objective:

Multiple myeloma (MM) associated with extramedullary (EM) plasmacytoma has a poor therapeutic response and poor outcomes when treated with conventional chemotherapy. EM plasmacytoma is divided into two groups: the first group comprises tumors that are extending directly from osteolytic bone lesions (EM-B, bone-related), while the second results from plasmacytoma infiltration into soft tissues with no relationship to the bone (EM-S, soft tissue-related). This study aimed to compare the general characteristics and survival outcomes of transplant-eligible MM patients who had EM-S or EM-B and MM patients who did not have plasmacytoma at the time of diagnosis.

Materials and Methods:

This study was performed in a retrospective manner. The MM patients who were treated at our tertiary care center between January 2003 and January 2017 were evaluated retrospectively for the presence of plasmacytoma at diagnosis.

Results:

There were 141 (78.3%) MM patients who did not have plasmacytoma, 22 (12.2%) MM patients who had EM-B, and 17 (9.4%) MM patients who had EM-S at the time of diagnosis in this study. The 5-year overall survival was 63% in patients who had bone EM-B, 63% in patients who had EM-S, and 80% in patients who did not have plasmacytoma (p=0.02). The 5-year disease-free survival was 47% in patients who had EM-B, 35% in patients who had EM-S, and 54% in MM patients who did not have plasmacytoma (p=0.15).

Conclusion:

These findings lead us to suggest that MM patients with EM plasmacytoma at the time of diagnosis have poorer prognosis than patients without plasmacytoma, even if autologous stem cell transplantation is performed. The presence of EM involvement negatively affects survival outcomes.

CIC Mutation as a Molecular Mechanism of Acquired Resistance to Combined BRAF-MEK Inhibition in Extramedullary Multiple Myeloma with Central Nervous System Involvement

Combined MEK-BRAF inhibition is a well-established treatment strategy in BRAF-mutated cancer, most prominently in malignant melanoma with durable responses being achieved through this targeted therapy. However, a subset of patients face primary unresponsiveness despite presence of the activating mutation at position V600E, and others acquire resistance under treatment. Underlying resistance mechanisms are largely unknown, and diagnostic tests to predict tumor response to BRAF-MEK inhibitor treatment are unavailable. Multiple myeloma represents the second most common hematologic malignancy, and point mutations in BRAF are detectable in about 10% of patients. Targeted inhibition has been successfully applied, with mixed responses observed in a substantial subset of patients mirroring the widespread spatial heterogeneity in this genomically complex disease. Central nervous system (CNS) involvement is an extremely rare, extramedullary form of multiple myeloma that can be diagnosed in less than 1% of patients. It is considered an ultimate high-risk feature, associated with unfavorable cytogenetics, and, even with intense treatment applied, survival is short, reaching less than 12 months in most cases. Here we not only describe the first patient with an extramedullary CNS relapse responding to targeted dabrafenib and trametinib treatment, we furthermore provide evidence that a point mutation within the capicua transcriptional repressor (CIC) gene mediated the acquired resistance in this patient. KEY POINTS: BRAF mutations constitute an attractive druggable target in multiple myeloma. This is the first genomic dissection of the central nervous system involvement in a multiple myeloma patient harboring a druggable BRAF^V600E mutation. Deep genomic characterization of the extramedullary lesion prompted a personalized therapeutic approach. Acquisition of CIC mutation confers a mechanism of BRAF-MEK inhibitor drug resistance in multiple myeloma. The in silico interrogation of the CoMMpass clinical study revealed 10 patients with somatic mutations of CIC and its downregulation at gene expression level in multiple myeloma. CIC gene silencing decreases the sensitivity of multiple myeloma cells to BRAF-MEK inhibition in vitro. The correlation between CIC downregulation and ETV4/5 nuclear factor expression in multiple myeloma BRAF-mutant cells is shown for the first time. CIC mutation, its downregulation, and the related downstream effect on MMP24 support disseminative potential providing new clues in the extramedullary biology definition.

Multiple Myeloma Breast Involvement: A Case Report

Multiple Myeloma involving the breast is very rare and the diagnosis is challenging because the clinical and radiological features of breast multiple myeloma are indistinguishable to other forms of breast disease whether primary or metastatic. In this article the authors report a case presented with breast masses, which were found to be extra osseous Multiple Myeloma. The patient was managed for multiple spinal lesions that were primarily thought to be metastasis from primary breast cancer.

Hematogenous extramedullary relapse in multiple myeloma - a multicenter retrospective study in 127 patients

The current study assesses the characteristics and outcomes of multiple myeloma (MM) patients, treated with novel agents for hematogenous extramedullary (HEMM) relapse. Consecutive patients diagnosed with HEMM between 2010-2018 were included. Patients' characteristics at diagnosis and at HEMM presentation, response to treatment, survival and factors predicting survival were recorded and analyzed. A group of 127 patients, all diagnosed with HEMM by imaging (87.3%) and/or biopsy (79%), were included. Of those, 44% were initially diagnosed with ISS3, 57% presented with plasmacytomas, and 30% had high-risk cytogenetics. Median time to HEMM was 32 months. In multivariate analysis, ISS3 and bone plasmacytoma predicted shorter time to HEMM (P = .005 and P = .008, respectively). Upfront autograft was associated with longer time to HEMM (P = .002). At HEMM, 32% of patients had no BM plasmacytosis, 20% had non-secretory disease and 43% had light-chain disease. Multiple HEMM sites were reported in 52% of patients, mostly involving soft tissue, skin (29%), and pleura/lung (25%). First treatment for HEMM included proteasome inhibitors (50%), immunomodulatory drugs (IMiDs) (39%), monoclonal antibodies (10%), and chemotherapy (53%). Overall response rate (ORR) was 57%. IMiDs were associated with higher ORR (HR 2.2, 95% CI 1.02-4.7, P = .04). Median survival from HEMM was 6 months (CI 95% 4.8-7.2). Failure to achieve ≥VGPR was the only significant factor for worse OS in multivariate analyses (HR = 9.87, CI 95% 2.35 - 39, P = .001). In conclusion, HEMM occurs within 3 years of initial myeloma diagnosis and is associated with dismal outcome. The IMiDs might provide a higher response rate, and achievement of ≥VGPR predicts longer survival.

Plasma cell myeloma positive for t(14;20) with relapse in the central nervous system

t(14;20)(q32;q11)/IGH-MAFB is a rare chromosomal abnormality in plasma cell myeloma (PCM), accounting for 1-2% of PCM cases. Patients with this translocation may have a poor prognosis. However, the clinicopathological features and response to novel agents have not been well clarified. We present a 63-year-old Japanese female with PCM positive for t(14;20). The tumor responded well to a proteasome inhibitor, bortezomib, and the patient achieved complete remission. Six months after remission, tumor relapse was noted in the left cerebellum and the right frontal lobe of the cerebrum. After whole brain radiation therapy, the tumor masses decreased in size. The patient was followed up with best-care support, but died of the disease 29 months after the initial PCM diagnosis. t(14;20)-positive PCM responded well to bortezomib at the time of the initial treatment. The CNS tumor involvement, which is rare in PCM, may be associated with the clinical aggressiveness of the t(14;20)-positive form of this myeloma.

Clinical effects of CD45 on the prognosis of extramedullary myeloma relapse

WHAT IS KNOWN AND OBJECTIVES

The incidence of extramedullary relapse (EMR) arising during the clinical course of multiple myeloma (MM) has increased in recent years. Therefore, we herein investigated the effects of immunophenotyping on the prognosis of MM patients with EMR.

METHODS

We conducted a retrospective review on data collected from MM patients with EMR between January 2007 and December 2018 at the Japanese Red Cross Society Wakayama Medical Center. Patient characteristics at the diagnosis of EMR, the prognostic significance of immunophenotyping and other factors were evaluated.

RESULTS AND DISCUSSION

Extramedullary relapse was detected in 55 of 231 patients (23.8%). At the diagnosis of EMR, CD45, the leucocyte common antigen, was detected in 54.5% of cases. CD45 negativity in bone marrow correlated with thrombocytopenia and higher serum LDH levels. Moreover, high-risk cytogenetics was more frequently observed in CD45- than in CD45+ patients. A univariate analysis showed that overall survival (OS) was significantly shorter in CD45- than in CD45+ patients. Thrombocytopenia, higher serum LDH levels and high-risk cytogenesis were also associated with shorter OS. A multivariate analysis confirmed that CD45 negativity, higher serum LDH levels and high-risk cytogenesis were independent adverse prognostic factors for OS. A Kaplan-Meier analysis revealed the potential of CD45- as a prognostic factor in patients with EMR and that it correlated with shorter survival.

WHAT IS NEW AND CONCLUSION

The present results showed that the expression of CD45 in the neoplastic plasma cells of MM patients with EMR was associated with patient prognosis independent of other prognostic factors. The establishment of a treatment strategy for EMR patients with CD45- MM cells is needed to improve poor outcomes.

A rare case of multiple myeloma with intracranial extramedullary relapse: One or more myeloma clones?

In a minority of relapsed myeloma, patient's disease may spread into extramedullary sites, associated with high degrees of heterogeneity. The breadth of myeloma therapeutic armamentarium allows clinicians to manage its heterogeneous presentation, including intracranial relapses, with fair success resulting in a significant prolongation of survival.

Imaging and bone marrow assessments improve minimal residual disease prediction in multiple myeloma

The value of minimal residual disease (MRD) status by bone marrow and imaging analysis as independent prognostic factors has been well established in multiple myeloma (MM). Nevertheless data about their potential complementarity for a more accurate assessment are limited. With this aim, we retrospectively analyzed the prediction of outcome with the combination of PET-CT and MRD, assessed by multiparameter flow cytometry (MFC) in 103 patients with newly diagnosed MM. We confirmed the benefit in terms of progression-free survival (PFS), linked to the achievement of negativity by MFC (hazard ratio [HR] 0.53; 95% confidence interval [CI]: 0.28-0.98), and PET-CT (HR 0.18; 95% CI: 0.09-0.36) individually. By combining both techniques, patients who became MRD-/PET-, with a median of PFS 92 months, had significant prolonged median PFS (P < .001). This is compared with MRD+/PET- and PET+ patients (median PFS of 45 and 28 months, respectively). We observed a significant difference (P = .003) in overall survival (OS) outcomes between MRD-/PET- and MRD+/PET- patients (4-year OS 94.2% and 100%, respectively), vs PET+ patients (4-year OS 73.8%). All survival results were confirmed in a conditional landmark analysis. These findings support the potential complementarity between PET-CT and MFC, and highlight their better predictive capability when improving sensitivity.

A Case of Aggressive Multiple Myeloma with Extramedullary Involvement of the Female Reproductive System, Thyroid and Breasts

Extramedullary disease at the time of diagnosis of multiple myeloma is a rare finding that portends poor prognosis and necessitates aggressive treatment strategies. We present a case of multiple myeloma with extramedullary plasmacytomas of the female reproductive system, thyroid and breasts. The patient was treated with lenalidomide, bortezomib, cyclophosphamide, and dexamethasone. Follow-up PET-CT scans confirmed clinical complete response, and the patient underwent autologous stem cell transplantation. The patient will be continued on lenalidomide and bortezomib maintenance therapy. To the best of our knowledge, simultaneous involvement of these sites has never been reported. The case highlights that there are no established guidelines on the treatment of multiple myeloma with extramedullary disease leading to great variability based on clinician preference. We will also discuss the treatment options and prognosis of multiple myeloma with extramedullary disease.

High-Risk Multiple Myeloma: Integrated Clinical and Omics Approach Dissects the Neoplastic Clone and the Tumor Microenvironment

Multiple myeloma (MM) is a genetically heterogeneous disease that includes a subgroup of 10–15% of patients facing dismal survival despite the most intensive treatment. Despite improvements in biological knowledge, MM is still an incurable neoplasia, and therapeutic options able to overcome the relapsing/refractory behavior represent an unmet clinical need. The aim of this review is to provide an integrated clinical and biological overview of high-risk MM, discussing novel therapeutic perspectives, targeting the neoplastic clone and its microenvironment. The dissection of the molecular determinants of the aggressive phenotypes and drug-resistance can foster a better tailored clinical management of the high-risk profile and therapy-refractoriness. Among the current clinical difficulties in MM, patients’ management by manipulating the tumor niche represents a major challenge. The angiogenesis and the stromal infiltrate constitute pivotal mechanisms of a mutual collaboration between MM and the non-tumoral counterpart. Immuno-modulatory and anti-angiogenic therapy hold great efficacy, but variable and unpredictable responses in high-risk MM. The comprehensive understanding of the genetic heterogeneity and MM high-risk ecosystem enforce a systematic bench-to-bedside approach. Here, we provide a broad outlook of novel druggable targets. We also summarize the existing multi-omics-based risk profiling tools, in order to better select candidates for dual immune/vasculogenesis targeting.

Diplopia and proptosis due to isolated lateral rectus plasmacytoma in a patient with multiple myeloma

Orbital involvement of multiple myeloma (MM) is uncommon, with most of those reported cases occurring at the time of initial diagnosis of MM. We present a case of an extramedullary plasmacytoma involving only the right lateral rectus of a patient who had been in disease remission. The patient presented with new-onset diplopia and an abduction deficit of the right eye, with mild proptosis. In light of her past medical history of MM, an orbital MRI was obtained. The MRI demonstrated an isolated finding of eccentric enlargement of the right lateral rectus muscle limited to the muscle belly with sparing of the tendinous insertions, leading to diagnosis of plasmacytoma. Patching of the involved eye to alleviate the symptoms of diplopia was instituted. Chemotherapy was initiated, followed by orbital radiation and stem-cell transplantation for coexisting systemic disease. The orbital symptoms of proptosis and diplopia resolved within 1 month of treatment.

A real world multicenter retrospective study on extramedullary disease from Balkan Myeloma Study Group and Barcelona University: analysis of parameters that improve outcome

Here, we report the outcome of 226 myeloma patients presenting with extramedullary plasmacytoma or paraosseous involvement in a retrospective study conducted in 19 centers from 11 countries. Extramedullary disease was detected at diagnosis or relapse between January 2010 and November 2017. Extramedullary plasmacytoma and paraosseous involvement were observed in 130 patients at diagnosis (92 of 38) and in 96 at relapse (84 of 12). The median time from multiple myeloma diagnosis to the development of extramedullary disease was 25.1 months (range 3.1-106.3 months) in the relapse group (median follow up: 15 months). Imaging approach for extramedullary disease was computed tomography (n=133), positron emission tomography combined with computed tomography (n=50), or magnetic resonance imaging (n=35). The entire group received a median two lines of treatment and autologous stem cell transplantation (44%) following the diagnosis of extramedullary disease. Complete response was higher for paraosseous involvement versus extramedullary plasmacytoma at diagnosis (34.2% vs. 19.3%; P=NS.) and relapse (54.5% vs. 9%; P=0.001). Also paraosseous involvement patients had a better progression-free survival (PFS) when recognized at initial diagnosis of myeloma than at relapse (51.7 vs. 38.9 months). In addition, overall survival was better for paraosseous involvement compared to extramedullary plasmacytoma at diagnosis (not reached vs. 46.5 months). Extramedullary plasmacytoma at relapse had the worst prognosis with a PFS of 13.6 months and overall survival of 11.4 months. In the multivariate analysis, paraosseous involvement, extramedullary disease at diagnosis, International Staging System (ISS-I), and undergoing autologous stem cell transplantation improved overall survival independently. This cohort demonstrated that extramedullary disease benefits from front-line autologous stem cell transplantation and extramedullary plasmacytoma differs from paraosseous involvement in terms of rate and duration of response, with even worse outcomes when detected at relapse, constituting an unmet clinical need.