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A 69-year-old man presented with lumbago and was diagnosed with multiple myeloma (IgD-λ type, R-ISS stage II) with bone-destructive lesions in the lumbar spine and sacrum. Chromosome analysis showed t (8;14)(q24;q32) and t (11;14)(q13;q32). Treatment with daratumumab, lenalidomide, and dexamethasone resulted in partial response, but the disease relapsed, with a copy number increase in t (11;14) and abnormal amplification of the 1q21 region. The patient was treated for CMV enteritis, and was admitted to the hospital due to sudden abdominal pain. Gastrointestinal perforation was diagnosed by CT scan showing free air and wall thickening in the small intestine. Emergency surgery was performed, and the tumors in the perforated area were positive for CCND1 but negative for MYC on immunostaining. The patient's general condition did not improve after the surgery and he died. Pathological autopsy revealed extramedullary infiltration of multiple organs in addition to the small intestine. Extramedullary infiltration is thought to be caused by clonal evolution, and further research is warranted to clarify its pathogenesis and establish effective therapeutic strategies in high-risk patients.

Multiple myeloma (MM) is a hematologic malignancy characterized by clonal proliferation of plasma cells. Recent advances in next-generation sequencing technologies have facilitated in-depth genetic exploration of MM, unveiling a more comprehensive genomic landscape that extends beyond classical chromosomal alterations, such as IGH translocations and hyperdiploidy. These studies have elucidated recurrent mutations across various functional pathways including those involving MAPK, NF-κB, cell cycle regulation, and epigenetic modulation. With respect to clinical utility, studies have shown that the number of genetic alterations and biallelic events in TP53 are associated with worse prognosis, and CRBN mutations with resistance to immunomodulatory drugs. We recently analyzed the full landscape of genetic alterations in relapsed and refractory MM using circulating tumor DNA (ctDNA), revealing TP53 mutations as the most frequent driver mutation. Notably, more than half of TP53 mutations were present in only ctDNA, suggesting a subclonal origin. Mutations in six genes, including KRAS and TP53, were associated with poor progression-free survival. In addition, the number of ctDNA mutations was identified as a prognostic factor independent of IGH translocations and clinical factors. Here we summarize recent progress in genetic analysis of MM, focusing on clinical relevance.

A 66-year-old man was diagnosed with symptomatic IgG-λ multiple myeloma based on the presence of anemia, thrombocytopenia, renal dysfunction, and a tumor on the right sixth rib. Bone marrow aspiration yielded a dry tap and biopsy revealed myelofibrosis grade 2. Partial response was achieved with Bd (bortezomib and dexamethasone) and VRd (bortezomib, lenalidomide, and dexamethasone). The patient received autologous stem cell transplantation, but the myeloma relapsed 3 months later, and liver tumors developed as well. DKd (daratumumab, carfilzomib, and dexamethasone) was administered, but the patient died due to disease progression. Autopsy revealed multiple extramedullary lesions in the liver, spleen, gallbladder, adrenal glands, kidneys, and multiple lymph nodes, as well as ascites.

Multiple myeloma (MM) is characterized by genomic instability, which causes multiple genetic and chromosomal alterations and leads to disease progression and therapeutic resistance. Overlapping mechanisms, including defective genome repair machinery such as the loss of TP53 activity, as well as chromosomal segregation error represented by the abnormality of mitotic checkpoint kinases such as BUB1, cell cycle dysregulation, and tumor environment, cause structural and numerical chromosomal abnormalities. Cytogenetic abnormalities are important prognostic factors, and they are also linked to the use of proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, and the BCL2 inhibitor venetoclax. We developed new diagnostic modalities for chromosomal analysis to improve the sensitivity and convenience of chromosomal diagnosis. The immunophenotyped-suspension-multiplex (ISM)-fluorescence in situ hybridization (FISH) can use imaging flow to examine three IGH-related chromosomal translocations at the same time. We also created a new FISH method called amplified FISH (amFISH) to detect microdeletion involving narrow chromosomal regions (approximately<100 kb), such as the microdeletions of 1p32 (CDKN2C) or of 14q32 (TRAF3), by using a fluorescent antibody to amplify the signals of small probes. Even in the era of clinical sequencing, these convenient modalities may hasten the cytogenetics-oriented therapeutic approach for MM.

A 75-year-old man developed multiple head masses as well as a compression fracture. His blood test revealed elevated immunoglobulin G (IgG) protein levels, and immunofixation electrophoresis revealed the presence of monoclonal IgGκ. Furthermore, positron emission tomography/computed tomography revealed multiple bone lesions, although bone marrow examination revealed only 1.2% of plasma cells. Biopsy of a head mass led to the diagnosis of plasmablastic lymphoma (PBL), an aggressive B-cell lymphoma with plasma cell phenotypes but no B-cell antigen expression. Because the tumor cells have plasmablastic morphologies, it is difficult to distinguish PBL from plasmablastic myeloma, which is a subtype of multiple myeloma. Both diseases have similar immunophenotypes and clinical courses. In this case, PBL was finally diagnosed based on Epstein-Barr virus positivity, and the patient made a complete recovery after treatment with DA-EPOCH.

A 71-year-old woman complained of nausea and anorexia. Laboratory tests revealed significant neutrophilia and immunoglobulin A-kappa type M proteinemia, as well as increased plasma cells on bone marrow examination. Furthermore, the serum granulocyte-colony stimulating factor (G-CSF) concentration was high at 160 pg/ml, and the colony stimulating factor 3 receptor (CSF3R)-T618I mutation was negative. Immunohistochemical (IHC) analysis of bone marrow specimens using the anti-G-CSF antibody revealed immunopositivity of some myeloma cells. The patient was diagnosed using G-CSF-producing myeloma and was treated with daratumumab, lenalidomide, and dexamethasone. Her treatment resulted in a very good partial response, with normalization of both serum G-CSF levels and neutrophil count. There have been a few cases of G-CSF -producing myeloma reported, and it has previously been reported as chronic neutrophilic leukemia with M proteinemia. According to previous reports, techniques such as serum G-CSF measurements, IHC with an anti-G-CSF antibody, and CSF3R gene mutation analysis are useful for differentiating G-CSF-producing myeloma. However, the clinical characteristics and long-term prognosis of G-CSF-producing myeloma remain unknown. Additional case gathering and investigations are required.

A 78-year-old man was treated with Bortezomib, Lenalidomide, and Dexamethasone, for multiple myeloma. Two years after the start of treatment, the patient came to our department with a complaint of gross hematuria. Cystoscopy revealed a tumor on the left wall of the bladder. Urine cytology was negative. Magnetic resonance imaging (MRI) of the lower abdomen showed a slightly high signal on the T2-weighted image, indicating an intravesical mass lesion invading outside the bladder. Contrast-enhanced computed tomography (CT) also showed an intravesical mass and enlarged left external iliac lymph node swelling. Transurethral resection of bladder tumor was performed. The resection specimen showed tumor cells. The pathological examination revealed CD138 (+) and light-chain restriction. The patient was diagnosed with plasmacytoma. The patient was treated with radiation therapy for plasmacytoma of the bladder and surrounding lymph nodes, and then with daratumumab and dexamethasone for multiple myeloma for one year; however, the patient died because of worsening of multiple myeloma.

An 88-year-old woman was diagnosed with multiple myeloma received third-line chemotherapy, including DBd (daratumumab [DARA], bortezomib, and dexamethasone [Dex]), and the myeloma was in remission. Sulfamethoxazole/trimethoprim (ST) prophylaxis was discontinued because the dose of Dex was reduced to 20 mg every 4 weeks after 21 cycles of DBd. After 28 cycles of DBd, altered consciousness with fever ensued, and she was referred to the emergency department where Listeria monocytogenes (LM) meningitis was diagnosed. CD38 inactivation is associated with increased LM susceptibility. In patients on Dara-based chemotherapy, antibiotic prophylaxis should be considered using ST, which has activity against Listeria.

Monoclonal gammopathy of undermined significance (MGUS) is usually asymptomatic, and untreated follow-up is the standard treatment. However, MGUS progresses to multiple myeloma or related malignancy at a frequency of 1.5% per year. It is sometimes difficult to diagnose the progression of the disease via usual examinations. We herein report a case wherein rapid renal dysfunction led to a diagnosis of disease progression to multiple myeloma in a patient with MGUS that was asymptomatic for a long time. A 66-year-old woman developed rapid renal dysfunction requiring continuous hemodiafiltration 8 years after the diagnosis of IgA-κ type MGUS. A complete examination led to the diagnosis of IgA-κ type multiple myeloma. Chemotherapy was not effective, and she died due to sepsis on the 19th day of admission. A pathological autopsy revealed systemic amyloidosis and multiple abscesses positive for Staphylococcus aureus. An abnormal free light chain κ/λ ratio and M protein other than IgG are reportedly risk factors of disease progression of MGUS. In cases with these risk factors, it is important to always keep in mind the possibility of disease progression and to monitor the patient carefully for an early diagnosis.

This paper reports a case of a 56-year-old male with IgG lambda plasmablastic myeloma exhibiting multiple chromosomal abnormalities. The patient initially presented with plasmablastic ascites and underwent early auto stem cell transplantation and achieved minimal residual disease-negative status but relapsed after 1.5 months and became refractory to novel drugs, such as proteasome inhibitor and daratumuab. Performing differential diagnosis of plasmablastic myeloma with extramedullary masses or fluid retention observed at the initial presentation in comparison to plasmablastic lymphoma and pleural effusion lymphoma is difficult, and patients often have a poor prognosis even with novel drugs. Hence, finding a treatment strategy for such patients is difficult. Thus, further novel drugs are expected to emerge in the future.

We present the case of a 67-year-old woman with meningeal carcinomatosis who was treated with chemotherapy for refractory multiple myeloma, and was in remission. She was admitted to our hospital because of tonic seizures and disturbance of consciousness. Monoclonal CD 138-positive plasma cells were detected in her cerebrospinal fluid. Cranial MRI showed gadolinium enhancement of diffuse meninges and cranial nerves. We diagnosed the patient with systemic epilepsy due to meningeal carcinomatosis and administered antiepileptic drugs and intrathecal chemotherapy; however, she showed little improvement, and she passed away on hospital day 74 because of disease progression. Multiple myeloma is known to be associated with neurological symptoms such as peripheral neuropathy, myelopathy, and radiculopathy; however, central nervous system involvement in multiple myeloma is uncommon. We should consider central nervous system involvement in multiple myeloma, such as meningeal carcinomatosis, given the importance of early detection and therapeutic intervention.

Recent advances in novel therapeutic agents, such as proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies, have markedly improved treatment outcomes in patients with multiple myeloma. The novel agent-based induction, followed by autologous transplantation, is considered as the standard treatment for transplant-eligible patients. Post-transplant consolidation and maintenance therapy can help maintain the subsequent response and further improve the treatment outcome in patients. Currently, there are several validated sensitive assays evaluating minimal residual disease (MRD), which have provided a means to quantitatively assess residual disease and accurately predict its prognosis in terms of progression-free and overall survival. Novel clinical studies that formally assess the effect of MRD negativity on clinical decision-making are ongoing. This session aims to provide an in-depth and comprehensive summary of the latest treatment strategy and MRD-based knowledge in newly diagnosed transplant-eligible patients with multiple myeloma.

Because multiple myeloma is rare in young people, there are fewer reports on the same. Thus, its clinical aspects and prognosis remain unelucidated. We retrospectively evaluated 30 patients with multiple myeloma aged ≤ 45 years at diagnosis. We divided them into three groups based on their cytogenetic risks: standard risk (SR), high risk (HR), and unknown risk. The frequency of HR patients was 36.6%, the highest of the three groups, unlike the previous report. The median progression-free survival (PFS) was 35 months (SR vs. HR, 46 vs. 29 months), and the median overall survival (OS) was not reached (NR) (SR vs. HR, NR vs. 82 months). The OS was significantly worse, and the PFS also appeared inferior in HR patients. The International Staging System score was not associated with OS. Thus, young patients with myeloma appeared to have a higher frequency of HR features, suggesting that instead of age, the cytogenetic risk was a significant prognostic factor.

Here, we present the case of a 72-year-old male who presented with swelling, stiffness, and dysesthesia in the bilateral fingers, wrists, and ankles. Although rheumatoid arthritis was initially suspected, laboratory tests were negative for rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody. Based on the findings of immune globulin G (IgG)-λ M proteins and 26% plasma cells in the bone marrow, multiple myeloma was diagnosed. Joint sonography revealed thickening of the tendon synovial sheaths around the bilateral wrist joints, palmar flexor tendon sheaths, and extensor digitorum tendon sheaths, and magnetic resonance imaging (MRI) revealed soft tissue masses around the bilateral hip joints. Carpal tunnel syndrome associated with amyloid arthritis was suspected. Amyloid deposits were observed in synovectomy specimens, and the patient was then diagnosed with amyloid arthritis. He had concurrent pulmonary fibrosis, and treatment with lenalidomide/dexamethasone (Ld therapy) was initiated. The symptoms in the bilateral fingers, wrists, and ankles improved with the treatment course, and joint sonography revealed that thickening of tendon sheath and soft tissue masses disappeared after seven courses of Ld therapy. However, MRI still revealed soft tissue masses around the bilateral hip joints. In patients with joint symptoms that do not fulfill the diagnostic criteria for rheumatoid arthritis, differentiation with amyloid arthritis is necessary.

A 51-year-old Brazilian female who had IgD-lambda type multiple myeloma presented with epigastralgia and obstructive jaundice during her follow-up. Contrast-enhanced computed tomography (CT) showed an enhanced mass of 25mm in the pancreatic head, and endoscopic retrograde cholangiopancreatography revealed smooth stenoses in the lower bile duct and main pancreatic duct (MPD) of the head. We diagnosed the patient with extramedullary pancreatic metastasis of multiple myelomas. Plastic stents were endoscopically placed into both the common bile duct and MPD. One week later, she suffered a repeat episode of epigastralgia. A subsequent CT scan showed obstructive pancreatitis due to another mass, 30mm in size, emerging rapidly in the pancreatic body. Pancreatitis improved after we replaced the plastic stent with a longer one so that the distal end reached beyond the stenosis at the MPD of the body. Although both the tumors were treated with radiotherapy and showed temporary reduction, the patient died 1 month later due to progression of the disease. While cases involving obstructive pancreatitis induced by extramedullary pancreatic metastasis of multiple myelomas are very rare, it is crucial that such patients are rapidly diagnosed and treated.

In a Japanese phase II study (MM-025), the efficacy and safety of lenalidomide plus low-dose dexamethasone (Rd) were confirmed at a median follow-up of 14.2 months in patients with newly diagnosed multiple myeloma who were ineligible for hematopoietic stem cell transplantation. In the present report, we analyzed the follow-up data from the abovementioned study. Treatment was stopped for all 26 patients after a median follow-up of 31.3 months, and the median treatment duration was approximately 25 months. The overall response rate was 87.5%, and the complete response rate was 20.8%. The median duration of response and progression-free survival were 30.7 and 31.6 months, respectively. The median overall survival has not yet been reached. At least one grade 3/4 adverse event was experienced by 23 patients (88.5%), and 18 patients (69.2%) experienced serious adverse events. There were no treatment-related deaths. Therefore, the efficacy and safety of Rd were confirmed in transplant-ineligible Japanese patients with newly diagnosed multiple myeloma at the present follow-up period.

The long-term outcome of multiple myeloma (MM) has been greatly improved by the advent of new agents such as proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs), despite the disease remaining mostly incurable. Treatment design is the critical determinant for the survival period and for the quality and way of life in patients with relapsed/refractory MM (RRMM). Recently, the choice of therapeutic options for RRMM has been expanded by the introduction of second generation PIs such as carfilzomib and ixazomib, and therapeutic monoclonal antibodies such as elotuzumab and daratumumab. In the choice of treatment strategies for RRMM, including stem cell transplantation, the decision should be based on an understanding of the characteristic clinical effects of each drug and the evaluation of the cytogenetic/molecular profile, myeloma-defining events, complications, and prior MM treatment history in individual patients.

There have been dramatic recent advances in understanding the basic pathophysiology and treatment strategies for multiple myeloma (MM). Research has shown both a high inter-patient diversity and intra-clonal heterogeneity even in a single patient in terms of cytogenetic/molecular abnormalities, and has also identified marked diversity in the immunological factors involved in tumor surveillance among MM patients. In the presence of a variety of novel agents, including molecular-targeted agents, immunomodulatory agents, and monoclonal antibodies, the optimal translation of current knowledge on both molecular and immunologic findings into clinical use is crucial for managing MM. In addition, the application of the decision-making process for the selection of treatment strategies, the classification of disease risk, the prediction of outcome, and disease status monitoring have greatly influenced the clinical course of MM. In this review, we summarize recent advances in understanding the pathophysiology of MM, including molecular/cytogenetic/epigenetic abnormalities and immunologic dysregulation of both tumor and immune cells. In addition, we also briefly discuss the changes/innovations in both diagnostic approaches and treatment concepts.

Meningococcal infection is among the most devastating diseases. It is rarely seen in Japan. However, several environmental and host factors have been associated with increased risks of Neisseria meningitidis infection. We present a case of invasive N. meningitidis infection that revealed the presence of multiple myeloma. A 55-year-old Japanese man was admitted with fever and altered consciousness. He was sent to the intensive care unit for septic shock and disseminated intravascular coagulation. In addition to standard septic shock and multiple organ failure treatment, polymyxin-B immobilized column direct hemoperfusion was performed. His blood culture was positive for N. meningitidis. The patient gradually improved and was discharged on day 35. We evaluated the risk factors for the development of meningococcal infection. A laboratory examination showed that the patient was negative for human immunodeficiency virus antibody and had a normal total complement function. However, his serum immunoglobulin G level was high, and serum and urine protein electrophoresis detected a monoclonal gammopathy. A bone marrow examination led to the diagnosis of multiple myeloma. Because N. meningitidis bacteria spreads between individuals in close contact through the exchange of oral secretions, droplet precautions and antimicrobial chemoprophylaxis (ciprofloxacin, 500 mg) were implemented to prevent the spread of the meningococcal infection. Sporadic meningococcal infection warrants an evaluation for immunodeficiency and the prevention of secondary infection.

Owing to the positive clinical benefits obtained with new agents, complete remission (CR) can be used as a surrogate for overall survival, and should be achieved. Although multiple myeloma is a heterogeneous disease in terms of myeloma cell- and patient-related risk factors, patients should receive the most effective combination therapy based on proteasome inhibitors and/or immunomodulatory drugs (IMiDs) as backbone medication irrespective of the risks encountered in the setting of induction therapy ("one-size-fits-all" therapy), followed by consolidation/maintenance therapy to achieve CR with the ultimate goal of extended survival. Myeloma-defining biomarkers have been established to identify high-risk smoldering myeloma requiring treatment. The development of salvage treatments yielding better outcomes for relapsed/refractory myeloma is urgently needed. Upcoming novel molecular targeting agents with different modes of action and immunotherapeutic agents will be integrated into myeloma treatment regimens with a great therapeutic impact, and further evolution of the treatment paradigm for multiple myeloma is eagerly anticipated.

Multiple myeloma (MM) has been diagnosed based on the International Myeloma Working Group (IMWG) diagnostic criteria since 2003. In 2014, the IMWG updated these diagnostic criteria to add three specific biomarkers, i.e., 1) Clonal bone marrow plasma cell percentage ≥60%; 2) Involved: uninvolved serum free light chain ratio ≥100; 3) >1 focal lesion on MRI studies, based on CRAB features (hypercalcemia, renal failure, anemia, and bone lesions). An early diagnosis of MM can be made, allowing timely anti-MM treatment, in patients with the ultra-high-risk smoldering form of this disease. This review focuses on the new IMWG diagnostic criteria for MM and evaluation of patients newly diagnosed with MM.

Autologous stem cell transplantation (ASCT) is known to be superior to conventional chemotherapies and has been established as a standard of care for young patients with multiple myeloma. In the first decade of this century, novel agents such as thalidomide, bortezomib, and lenalidomide became clinically available, and several clinical trials using these drugs as induction therapies, conditioning regimens, and post-transplant consolidation and maintenance therapies have been reported, leading to increasing improvement in treatment results as compared to conventional therapies. Future changes in therapeutic strategies using these novel agents are anticipated to increase the complete response rate and prolong progression free survival and overall survival. This article describes the optimal treatment strategy for ASCT-eligible patients in Japan.

In the past decade, previously approved novel agents, such as proteasome inhibitors (bortezomib) and immunomodulatory drugs ([IMiDs]; e.g., lenalidomide), have led to significant improvement in the treatment of multiple myeloma in Japan. However, almost all patients will ultimately relapse, even when they have achieved a deep and prolonged therapeutic response with initial treatment. Next-generation IMiDs (pomalidomide) and deacetylase inhibitors (panobinostat) were approved for use as salvage therapy for refractory and relapsed multiple myeloma [RRMM] within the last year. Long-term chemotherapy could result in the emergence of drug-resistant clones due to "intraclonal heterogeneity" and "clonal evolution by Darwinian selection." Though some recommendations on the management of RRMM have been detailed, no uniform treatment has yet been established for these patients. Relapse situations are heterogeneous. Therefore, relapse management requires an individual approach based on assessments of patient-, disease-, and treatment-related factors. The primary considerations when selecting an appropriate treatment are patient-related factors such as frailty, comorbidity, disability, quality of life, and the overall goals of care. We hope that these novel agents that appear promising in Japan, such as monoclonal antibodies (e.g., elotuzumab, daratumumab) and next-generation proteasome inhibitors (e.g., carfilzomib, ixazomib) will improve the outcomes of patients with this incurable disease in the near future.

The current therapeutic strategy for multiple myeloma has improved dramatically due to the use of novel agents. In newly diagnosed transplant-ineligible myeloma patients, the standard therapy until the 1990s had long been melphalan and prednisolone (MP), but the recent recommendation is the proteasome inhibitor bortezomib plus MP (MPB), the immunomodulatory drug thalidomide plus MP (MPT), and the thalidomide derivative lenalidomide (LEN)-based regimens such as LEN plus low-dose dexamethasone (Ld) and LEN plus MP (MPL). The overall response rate in patients treated with Ld, MPL, or MPB was reported to be approximately 70%. Achieving complete remission (CR) is important in elderly as well as younger patients. Therefore, MPB administration appears to be the most appropriate initial therapy because the MPB regimen results in high CR rates. However, in elderly patients, especially in those 75 years of age and older and those who are frail or with comorbidities, it is important to balance efficacy and toxicity as well as to maintain quality of life. Furthermore, continuous treatment results in longer survival than a fixed-duration regimen in this population.

CD138 has been considered to be strongly expressed in multiple myeloma cells. However, CD138⁺ cells were decreased in some patients during the course of treatment. To clarify the clinical significance of this finding, we evaluated the correlations of CD138 levels with laboratory data employing flow cytometry. We found that CD138⁺ cells were decreased in 12 patients during treatment and were retained in the remaining 105 patients throughout their clinical courses. For nine (75%) patients in the CD138⁺ cells reduced group, median survival time was 25 months after the reduction in CD138⁺ cells was detected, and all nine died of myeloma. Furthermore, extramedullary lesions and specific cytogenetic abnormalities [del(17p), t(4;14), amplification of c-MYC] were observed in some patients when the number of CD138⁺ cells started to decrease. Interestingly, 2 of 3 patients who survived until the end of observation period showed re-increase in their CD138⁺ levels. Taking these observations together, it is unclear whether reduction of the number of CD138⁺ cells is associated with a poor prognosis and resistance to drugs. However, if treatment does not produce a reincrease in CD138⁺ levels, long term survival might be difficult to achieve.

We carried out a cohort study of smoldering multiple myeloma (SMM) in Japan. The clinical data of 207 patients with SMM, median age 69 years (range: 27-90), were collected from 63 institutions. The subtype of myeloma was IgG type in 168, IgA type in 30, and Bence Jones type in 9 patients. At a median follow-up of 39 months, 53% of the patients had progressed to symptomatic MM (within 5 years of the initial diagnosis). As previously described, a serum free light chain ratio>8 or <0.125, along with the number of bone marrow plasma cells being 10% or more and the serum M-protein level being at least 3 g/dl, was a significant predictor of rapid progression. We found that the rate of increase in serum M-protein levels correlated negatively with the risk of progression. The probability of progression within 5 years was 100% in patients whose rate of serum M-protein level increase was 2 mg/dl/day or higher. This indicates that the serum M-protein level increase rate might be a useful predictor of disease progression in SMM.

A 52-year-old woman was diagnosed with BJP-λ multiple myeloma (MM) in November 2012. She was treated with six cycles of bortezomib and dexamethasone, resulting in a very good partial response. The patient underwent autologous peripheral blood stem cell transplantation (PBSCT) 6 months after the diagnosis, and clearly achieved a complete response thereafter. She again suffered chronic abdominal pain with spontaneous remission 9 months after the PBSCT, and, 2 months thereafter, was hospitalized due to intestinal obstruction. Two small intestinal intussusceptions and polyposis in the small intestine were found on abdominal computed tomography. As conservative treatment produced no improvement, partial resection of the small intestine was performed. The pathologic review clearly demonstrated the polyps to have atypical plasma cell infiltrates in the mucosa of the small intestine involving all layers. Immunohisto-chemistry and FISH analyses yielded positive results for CD138, CD79a, and λ light chain, consistent with extramedullary relapse of MM. It is very rare for MM to present with polyposis in the small intestine. There have been no reports describing such a case after autologous PBSCT.

A 14-year-old male with multiple myeloma (IgG-λ, ISS stage 3) received myeloablative matched unrelated bone marrow transplantation, and achieved a complete response. At 16 months after the transplantation, he relapsed. The relapse was resistant to bortezomib and thalidomide. Peripheral blood showed mixed chimerism with 10% recipient cells. Peripheral blood stem cells (PBSC) were collected and pseudo-autologous PBSC transplantation (PASCT) was performed following high-dose melphalan without graft-versus-host disease prophylaxis. Hematopoietic recovery was prompt and a partial response was obtained without graft-versus-host disease exacerbation. We have presented a rare case of adolescent-onset multiple myeloma, obtaining a transient response with PASCT following post-allogeneic transplant relapse.

Recent meta-analyses and systematic reviews focusing on the significance of high dose therapy with autologous hematopoietic stem cell transplantation for newly-diagnosed multiple myeloma patients have shown its benefit in terms of progression-free survival, but no over-all survival benefit versus conventional chemotherapy. New drug-containing regimens, with agents such as iMIDs and proteasome inhibitors, have not yet been established as high-dose therapy, because no phase III RCT has been conducted to date. Although several guidelines recommend maintenance therapy for non-CR patients after transplantation, caution is still warranted because the JSH guideline advocates further careful discussion of this clinical question.

CD 20 positive myeloma with small lymphoplasmacytoid morphology is difficult to differentiate from mature B-cell lymphoma. A 71-year-old male was referred to our hospital because of osteolytic vertebral fractures and anemia. Urine was positive for Bence Jones protein, κ type. Bone marrow consisted of approximately 30% small lymphoplasmacytoid cells with scant cytoplasm, and these cells were positive for CD20, CD23 and CD138. FISH analysis revealed t(11;14)(CCND1/IGH). Myeloma with t(11;14) is closely associated with small lymphoplasmacytoid appearance and CD20 and CD23 expressions. The patient was diagnosed as having myeloma based on clinical and cytogenetic findings, and achieved VGPR (very good partial response) after treatment with lenalidomide.

In the past decade, the introduction of bortezomib, thalidomide, and lenalidomide has changed the treatment of multiple myeloma (MM) dramatically. Combinations of bortezomib or lenalidomide with dexamethasone have improved response rates and prolonged response duration compared with older approaches. However, many patients will relapse, and efforts to improve survival are still needed. Several clinical studies have demonstrated that bortezomib- or lenalidomide-based triplet regimens have improved activity compared with doublet regimens. Bortezomib and lenalidomide have different but overlapping mechanisms of anti-MM activity in preclinical studies. In several studies, the triplet regimens of lenalidomide, bortezomib, and dexamethasone (RVD) have shown significant efficacy and favorable tolerability in both newly diagnosed and relapsed/refractory multiple myeloma. In this review, we will focus on RVD therapy for myeloma treatment.