Early Detection and Diagnostic Approach Through Automated Hematological Analysis for Plasma Cell Leukemia

Plasma cell leukemia (PCL) is a clinically aggressive variant of multiple myeloma, characterized by a high burden of circulating plasma cells, necessitating swift and accurate diagnosis due to its poor prognosis. The conventional diagnostic criteria, including the recent recommendation by the International Myeloma Working Group (IMWG) of > 5% circulating plasma cells as positive, have evolved over time. In this context, we present a detailed case report that underscores the pivotal role of the ADVIA 2120 automated hematology counter in detecting plasma cells through cytogram analysis, along with the significance of routine peripheral blood smear analysis and the utility of a large unstained cells (LUCs) threshold of > 4.5% as an indicator for PCL. The case involves a 64-year-old patient with relapsed multiple myeloma and stable paraprotein levels who experienced sudden renal impairment. In this case report, we highlight how ADVIA analysis and cytochemistry assisted in the diagnosis, and further explore ADVIA's utility in this challenging leukemia.

Efficacy and Safety Analysis of VRD-PDCE in Treatment-Native Patients with Multiple Extramedullary Plasmacytomas or Plasma Cell Leukemia

The prognosis of multiple extramedullary plasmacytomas (MEP) and plasma cell leukemia (PCL) is extremely poor, with the median overall survival (OS) of only 8 months with standard chemotherapy. Innovative treatment approaches incorporating various strategies are required to improve outcome. From November 2019 to September 2021, a total of 12 newly diagnosed MEP or PCL patients were enrolled in our department. An intensive chemotherapy treatment as VRD-PDCE consisted of bortezomib, lenalidomide, dexamethasone plus cisplatin, pegylated liposomal doxorubicin, cyclophosphamide and etoposide was first proposed. Disease activity and toxicity were evaluated after each cycle. Of the patients receiving therapy achieved a rapid and sustained response, and the overall response rate (ORR) was up to 75%. Nine patients achieved partial response (PR) or better, the response was the best response and the median time to best response was 4 cycles. Median overall survival (OS) and progression-free survival (PFS) were 24 (5-30) months and 18 (2-23) months. The toxicities were acceptable and there was no treatment related mortality. Our intensive treatment showed encouraging results in terms of disease control and improving survival, VRD-PDCE may be a novel regimen which is feasible and generally well-tolerated in MEP or PCL patients.

Coincidence of plasma cell leukemia and COVID-19: a diagnostic pitfall

We report the case of a 66-year-old man with a known history of IgD multiple myeloma (MM) which was admitted to hospital because of acute renal failure. Routine PCR testing on admission yielded a positive result for SARS-CoV-2 infection. Examination of the peripheral blood (PB) smear revealed 17% lymphoplasmacytoid cells and a few small plasma cells mimicking morphological changes frequently seen in viral diseases. However, flow cytometric examination showed 20% clonal lambda-restricted plasma cells being consistent with a diagnosis of secondary plasma cell leukemia. Circulating plasma cells as well as similar appearing lymphocyte subtypes such as plasmacytoid lymphocytes are frequently observed in infectious disorders such as COVID-19, so that the lymphocyte morphology in our patient's case could have been easily misinterpreted as typical COVID-19-induced changes. Our observation highlights the importance of incorporating clinical, morphological, and flow-cytometric data in distinguishing between reactive and neoplastic lymphocyte changes because misinterpretation may affect disease classification and, beyond that, clinical decision-making, which may have serious consequences for patients.

Progression of Hodgkin lymphoma and plasma cell neoplasms: Report from the 2021 SH/EAHP Workshop

OBJECTIVES

To summarize cases submitted to the 2021 Society for Hematopathology/European Association for Haematopathology Workshop under the categories of progression of Hodgkin lymphoma, plasmablastic myeloma, and plasma cell myeloma.

METHODS

The workshop panel reviewed 20 cases covered in this session. In addition, whole-exome sequencing (WES) and whole-genome RNA expression analysis were performed on 10 submitted cases, including 6 Hodgkin lymphoma and 4 plasma neoplasm cases.

RESULTS

The cases of Hodgkin lymphoma included transformed cases to or from various types of B-cell lymphoma with 1 exception, which had T-cell differentiation. The cases of plasma cell neoplasms included cases with plasmablastic progression, progression to plasma cell leukemia, and secondary B-lymphoblastic leukemia. Gene variants identified by WES included some known to be recurrent in Hodgkin lymphoma and plasma cell neoplasm. All submitted Hodgkin lymphoma samples showed 1 or more of these mutations: SOCS1, FGFR2, KMT2D, RIT1, SPEN, STAT6, TET2, TNFAIP3, and ZNF217.

CONCLUSIONS

Better molecular characterization of both of these neoplasms and mechanisms of progression will help us to better understand mechanisms of progression and perhaps develop better prognostic models, as well as identifying novel therapeutic targets.

Hyperfractionated Cyclophosphamide and Dexamethasone Alone or in Combination with Daratumumab and/or Carfilzomib for the Treatment of Relapsed or Refractory Multiple Myeloma: A Single-Center Retrospective Analysis

BACKGROUND

Hyperfractionated cyclophosphamide and dexamethasone (HyperCd) alone, or with carfilzomib(K) and/or daratumumab(D), represents a potential treatment option when rapid disease control is needed for patients with aggressive presentations of relapsed/refractory multiple myeloma (RRMM).

PATIENTS AND METHODS

This is a single-center, retrospective analysis of adult patients with RRMM who received HyperCd with or without K and/or D between May 1, 2016 and August 1, 2019 at the University of Texas MD Anderson Cancer Center. We here report treatment response and safety outcomes.

RESULTS

Data from 97 patients, 12 with plasma cell leukemia (PCL), were reviewed in this analysis. Patients had had a median of 5 prior lines of therapy and received a median of 1 consecutive cycle of hyperCd-based therapy. The overall response rate (ORR) of all patients was 71.8% (HyperCd 75%, HyperCdK 64.3%, D-HyperCd 73.3%, and D-HyperCdK 76.9%). Median progression-free survival and overall survival among all patients was 4.3 months (HyperCd 3.1 months, HyperCdK 4.5 months, D-HyperCd 3.3 months, and D-HyperCdK 6 months) and 9.0 months (HyperCd 7.4 months, HyperCdK 9.0 months, D-HyperCd 7.5 months, and D-HyperCdK 15.2 months), respectively. Grade 3/4 hematologic toxicities were common, thrombocytopenia being the most frequent at 76%. Notably, 29-41% of patients per treatment group had existing grade 3/4 cytopenias at initiation of hyperCd-based therapy.

CONCLUSION

HyperCd-based regimens provided rapid disease control among MM patients, even when heavily pre-treated and with few remaining treatment options. Grade 3/4 hematologic toxicities were frequent, but manageable with aggressive supportive care.

Isolated relapse of plasma cell leukemia in the central nervous systems: a case report and literature review

Plasma cell leukemia is a rare yet aggressive form of multiple myeloma characterized by high levels of plasma cells circulating in the peripheral blood. We recently experienced a case of plasma cell leukemia that had been in stringent complete remission for nine years after autologous stem cell transplantations with subsequent courses of lenalidomide maintenance therapy, and then relapsed as an extramedullary plasmacytoma in the central nervous system. Assessment of the bone marrow did not prove proliferation of plasma cells at relapse, but imbalanced elevation of serum levels of free light chains was observed without changes in other clinical biomarkers including immunoglobulin levels. Salvage chemotherapy with isatuximab, pomalidomide, and dexamethasone (IsaPD) was promptly initiated. After two courses of IsaPD, significant remission was achieved and the neuronal symptoms completely resolved. When excessive serum levels of clonotypic free light chains are noted, their significance should be carefully assessed even when plasma cell propagation in the bone marrow is not observed. In such cases, hematologists should search for extramedullary proliferation of plasma cells, including in the immune-privileged central nervous system.

Rapidly Progressing Plasma Cell Leukemia with Underlying Plasmablastic Morphology: A Rare Case Report of a 25-Year Old Male

Multiple myeloma constitutes a wide spectrum of diseases, ranging from slow-growing monoclonal gammopathy of undetermined significance to rapidly progressing plasma cell leukemia. It is a very rarely diagnosed hematological malignancy in those less than 30 years of age. A 25-year-old male presented with complaints of fatigue and low-grade fever. On investigation, he was found to have bicytopeina and features of tumor lysis syndrome. Initially, this was thought to be indicative of acute leukemia. However, upon further analysis with bone marrow biopsy, serum protein electrophoresis, and immunofixation, it was determined that the patient had an IgG myeloma with plasmablastic morphology. It rapidly progressed and the peripheral smear started showing clusters of plasma cells suggesting a picture of plasma cell leukemia. The patient succumbed to this aggressive disease despite treatment. This case illustrates that myeloma should also be included in the differential diagnosis for young patients, especially the rare plasmablastic variant, which can be misdiagnosed as acute leukemia. The aggressive morphology also tends to show rapid progression to plasma cell leukemia, which has a poor prognosis.

Update on primary plasma cell leukemia

Plasma cell leukemia (PCL) is a rare and highly aggressive plasma cell neoplasm developing in 0.5?4% of patients with multiple myeloma (MM). The diagnostic criteria were recently revised from 20% to ≥5% of circulating plasma cells in peripheral blood smears. PCL is classified as primary or secondary; primary PCL is when it presents in patients with no MM. Primary PCL shows clinical and laboratory features at presentation that differ from MM and exhibits a dismal prognosis even with the use of effective agents against MM. Therefore, intensive chemotherapy should be initiated immediately after diagnosis, and autologous stem cell transplantation is recommended for transplant-eligible patients. Maintenance therapy after transplantation may reduce the rate of early relapses. We reviewed the definitions of PCL, revised diagnostic criteria, clinical features, and appropriate initial treatments for primary PCL.

Multiple myeloma: a review of atypical imaging features and other distinct plasma cell disorders that demonstrate similar imaging features

Multiple osteolytic lesions are a well-recognized and typical imaging feature of multiple myeloma as well as several other plasma cell disorders. Given the high volume of imaging studies obtained of multiple myeloma patients, radiologists will likely encounter a subset of multiple myeloma patients with less common or "atypical" findings during their practice. These atypical findings include osteosclerotic lesions, extramedullary lesions, and amyloid deposition. Similar imaging findings that are considered atypical for multiple myeloma can also be detected in other plasma cell disorders that are distinct from multiple myeloma. For instance, POEMS syndrome is a distinct plasma cell disorder from multiple myeloma, but also can present with osteosclerotic lesions. This article reviews the atypical findings associated with multiple myeloma and also reviews other plasma cell disorders that can have a similar spectrum of imaging findings. Special attention is paid to the musculoskeletal imaging findings.

[PAX5-positive plasma cell leukemia presenting as lymphocytosis]

An 82-year-old Japanese male patient was initially diagnosed with lymphocytosis. His complete blood count revealed a white blood cell count of 30.9×10⁹/l with 81% abnormal lymphocytes. The abnormal lymphocytes included monoclonal clones of CD38⁺ and CD138⁺cytoplasmic κ⁺ and IgG-κ M-protein, which led to the final diagnosis of plasma cell leukemia (PCL). Bortezomib and dexamethasone therapy was initiated, but the patient succumbed to the disease on the 8th day of hospitalization. A cytogenetic examination revealed a t (9;14)(p13;q32) translocation and the Western blotting confirmed high PAX5 expression. Similar to our present case, PCL cases with "lymphocytosis" have been widely reported, which some speculating the involvement of PAX5 overexpression in the pathogenesis. Such cases, including ours, may be classified as a unique group of disorders (PCL presenting as "lymphocytosis"), which requires accurate differential diagnosis and subsequent urgent multidisciplinary intensive treatment.

Metastatic plasma cell leukemia to the skin: A case report with review of the literature

Plasma cell leukemia (PCL) is a rare variant of leukemia with an aggressive clinical course and a poor prognosis. The cutaneous involvement in PCL is very rare either at clinical presentation of leukemia, namely leukemia cutis, or in the metastatic PCL to the skin. We present a case of eruptive multiple cutaneous nodules in a 56-year-old man with metastatic PCL. Histologically, a diffuse dermal and subcutaneous infiltration of ovoid cells with amphophilic cytoplasm and eccentrically located nucleus consistent with plasmacytoid morphology was observed. Neoplastic cells showed strong immunoexpression for CD138 and CD38 consistent with plasma cells phenotype, and loss of expression of CD56. Kappa light chain restriction similar to the phenotype of his PCL was demonstrated. We suggest that the evaluation of new skin lesions in leukemic patients should include a histopathologic examination to establish the diagnosis as soon as possible and a correct management of the disease.

Acute Plasma Cell Leukemia Presenting as Primary Hyperammonemic Encephalopathy

Primary plasma cell leukemia (PPCL) is a rare form of multiple myeloma (MM) and is a rare aggressive disease with a median overall survival of 6 - 11 months. We present a case of acute hyperammonemic encephalopathy as the initial presentation of PPCL in a 78-year-old woman to highlight an atypical presentation of this disorder.

Plasma cell leukemia: A review of the molecular classification, diagnosis, and evidenced-based treatment

Plasma cell leukemia is a rare and aggressive plasma cell dyscrasia associated with dismal outcomes. It may arise de novo, primary plasma cell leukemia, or evolve from an antecedent diagnosis of multiple myeloma, secondary plasma cell leukemia. Despite highly effective therapeutics, survival for plasma cell leukemia patients remains poor. Molecular knowledge of plasma cell leukemia has recently expanded with use of gene expression profiling and whole exome sequencing, lending new insights into prognosis and therapeutic development. In this review, we describe the molecular knowledge, clinical characteristics, evidenced-based therapeutic approaches and treatment outcomes of plasma cell leukemia.

Management of Primary Plasma Cell Leukemia Remains Challenging Even in the Era of Novel Agents

Primary plasma cell leukemia (PCL) is a rare and aggressive variant of multiple myeloma (MM). PCL is characterized by peripheral blood involvement by malignant plasma cells and an aggressive clinical course leading to poor survival. There is considerable overlap between MM and PCL with respect to clinical, immunophenotypic, and cytogenetic features, but circulating plasma cell count exceeding 20% of peripheral blood leukocytes or an absolute plasma cell count of >2000/mm³ distinguishes it from MM. After initial stabilization and diagnosis confirmation, treatment of PCL in a fit patient typically includes induction combination chemotherapy containing novel agents typically, with proteasome inhibitors (such as bortezomib) and immunomodulatory drugs (eg, lenalidomide), followed by autologous hematopoietic stem cell transplant (HSCT) and multidrug maintenance therapy using novel agents post-HSCT. Long-term outcomes have improved employing this strategy but the prognosis for non-HSCT candidates remains poor and new approaches are needed for such PCL patients not eligible for HSCT. Here, we report a case of primary PCL, and a comprehensive and up to date review of the literature for diagnosis and management of PCL. We also present the findings of Positron Emission Tomography (PET) scan. Since PCL is often associated with extra-medulary disease, including PET scan at the time of staging and restaging may be a novel approach particularly to evaluate the extra-medullary disease sites.

[Prevalence investigation of plasma cell leukemia in China: a calculation based on national urban medical insurance in 2016]

目的

分析我国城市人口中浆细胞白血病（PCL）的流行病学特征，并测算2016年PCL患病率。

方法

利用我国23个省2016年1月1日至2016年12月31日的城镇基本医疗保险数据进行测算。利用医疗保险数据中的疾病诊断名称和疾病诊断编码识别PCL患者。按性别、地区和年龄进行亚组分析，并通过敏感性分析考察结果的稳健性。基于我国2010年全国人口普查数据计算按年龄调整的标准化患病率。

结果

2016年我国城市人口中PCL患病率为0.11/10万（95％CI 0.05～0.19），其中男性和女性患病率分别为0.12/10万（95％CI 0.06～0.21），0.10/10万（95％CI 0.04～0.19）。PCL的患病率在70～79岁时达高峰。敏感性分析显示本研究结果具有稳健性。根据我国2010年全国人口普查数据所得的标化患病率为0.12/10万（95％CI 0.11～0.13）。

结论

本研究首次利用全国城镇医疗保险数据测算我国PCL的患病率，为PCL相关研究和政策制定提供依据。

[Successful disease control of plasma cell leukemia by the treatment comprising proteasome inhibitors, followed by daratumumab, lenalidomide, and dexamethasone therapy]

A 59-year-old woman was referred by her family doctor to our hospital owing to anemia, nausea, and malaise. She was diagnosed with primary plasma cell leukemia based on her laboratory and morphologic findings. She was treated with high dose of dexamethasone; cyclophosphamide, bortezomib, and dexamethasone; and carfilzomib, lenalidomide, and dexamethasone. She achieved partial treatment response. We switched her treatment to daratumumab, lenalidomide, and dexamethasone (DRd) owing to progression of peripheral neuropathy. Bone marrow examination performed after 15 courses of DRd revealed minimal residual disease-negative status. Sequential multidrug combination chemotherapies may be related to long-term successful disease control.

Successful upfront cord blood transplantation for plasma cell leukemia in the first complete response after daratumumab therapy

Plasma cell leukemia (PCL) is a rare and aggressive disease with a poor prognosis. Autologous or allogeneic stem cell transplantation (ASCT or allo-SCT) with intensive chemotherapy is performed for PCL, but their efficacy is still controversial. The efficacy of novel agents such as daratumumab for PCL is also unclear. Here, we report a case of PCL treated successfully with daratumumab and upfront cord blood transplantation (CBT) in the first complete response (CR). A 58-year-old man was diagnosed with PCL based on elevated abnormal plasma cells and IgD levels. After two cycles of bortezomib, lenalidomide, and dexamethasone therapy, some PCL cells remained in the bone marrow. We switched treatment to daratumumab, lenalidomide, and dexamethasone therapy and confirmed an immunophenotypic CR. We then performed CBT with fludarabine, melphalan, and total body irradiation for conditioning 3 months after diagnosis. Acute graft-versus-host disease was observed but controlled with corticosteroid therapy. The patient remained in stringent CR for 1 year after CBT. We successfully treated PCL with daratumumab followed by upfront CBT. Daratumumab was effective in PCL and could be used safely even before allo-SCT. Early use of daratumumab and early upfront allo-SCT may be a useful treatment option for PCL.

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.

Outcomes with Autologous or Allogeneic Stem Cell Transplantation in Patients with Plasma Cell Leukemia in the Era of Novel Agents

Plasma cell leukemia (PCL) is a rare and very aggressive plasma cell disorder. The optimal treatment approach, including whether to pursue an autologous (auto) or allogeneic (allo) stem cell transplantation (SCT) is not clear, given the lack of clinical trial-based evidence. This single-center retrospective study describes the outcomes of 16 patients with PCL (n = 14 with primary PCL) who underwent either autoSCT (n = 9) or alloSCT (n = 7) for PCL in the era of novel agents, between 2007 and 2019. The median age of the cohort was 58 years. High-risk cytogenetics were found in 50% of the patients. All patients received a proteasome inhibitor and/or immunomodulatory drug-based regimen before transplantation. At the time of transplantation, 10 patients (62%) obtained at least a very good partial response (VGPR). The response after autoSCT (3 months) was at least a VGPR in 6 patients (67%; complete response [CR] in 5). All patients undergoing alloSCT achieved a CR at 3 months. Maintenance therapy was provided to 5 patients (56%) after autoSCT. The median progression-free survival after transplantation was 6 months in the autoSCT group, compared with 18 months in the alloSCT group (P = .09), and median overall survival (OS) after transplantation in the 2 groups was 19 months and 40 months, respectively (P = .41). The median OS from diagnosis was 27 months and 49 months, respectively (P = .50). Of the 11 deaths, 10 patients (91%) died of relapsed disease. AlloSCT was not observed to offer any significant survival advantage over autoSCT in PCL, in agreement with recent reports, and relapse remains the primary cause of death in these patients.

Bortezomib-induced diffuse alveolar hemorrhage in a patient with plasma cell leukemia

Bortezomib, a chemotherapeutic agent used in the treatment of hematologic malignancies, has been associated with multiple forms of lung injury including diffuse alveolar hemorrhage (DAH). We present the first reported case of bortezomib-induced DAH in a patient with plasma cell leukemia. This 59-year-old female developed hemoptysis, severe cough, and diffuse bilateral ground glass opacities on CT scan of the chest after receiving one dose of bortezomib, with DAH subsequently confirmed on bronchoalveolar lavage. Unlike most previously reported cases, she did not develop respiratory failure requiring high dose corticosteroids, and in fact did not require any supplemental oxygen. We also provide a comparative summary of all reports of bortezomib-induced DAH in the literature to date. This case provides additional insight into the spectrum of disease severity observed in DAH secondary to bortezomib therapy.

Plasma Cell Leukemia - Facts and Controversies: More Questions than Answers?

Plasma cell leukemia (PCL) is an aggressive hematological malignancy characterized by an uncontrolled clonal proliferation of plasma cells (PCs) in the bone marrow and peripheral blood. PCL has been defined by an absolute number of circulating PCs exceeding 2.0 × 10⁹/L and/or >20% PCs in the total leucocyte count. It is classified as primary PCL, which develops de novo, and secondary PCL, occurring at the late and advanced stages of multiple myeloma (MM). Primary and secondary PCL are clinically and biologically two distinct entities. After the diagnosis, treatment should be immediate and should include a proteasome inhibitor and immunomodulator-based combination regimens as induction, followed by stem cell transplantation (SCT) in transplant-eligible individuals who have cleared the peripheral blood of circulating PCs. Due to the rarity of the condition, there have been very few clinical trials. Furthermore, virtually all of the myeloma trials exclude patients with active PCL. The evaluation of response has been defined by the International Myeloma Working Group and consists of both acute leukemia and MM criteria. With conventional chemotherapy, the prognosis of primary PCL has been ominous, with reported overall survival (OS) ranging from 6.8 to 12.6 months. The use of novel agents and autologous SCT appears to be associated with deeper response and an improved survival, although it still remains low. The PCL prognostic index provides a simple score to risk-stratify PCL. The prognosis of secondary PCL is extremely poor, with OS of only 1 month.

Primary Plasma Cell Leukemia: Real-World Retrospective Study of 46 Patients From a Single-Center Study in China

BACKGROUND

Primary plasma cell leukemia (PPCL) is a rare and aggressive plasma cell disorder. The use of novel agents, together with autologous stem cell transplantation, has improved survival outcome in PPCL. However, the prognosis is still very poor, and the optimal treatment remains an unmet clinical need.

PATIENTS AND METHODS

We studied the efficacy and prognostic impact of novel agents in 46 patients with PPCL patients at the Blood Diseases Hospital in China. We examined the impact of clinical and laboratory features, as well as therapies (bortezomib- and/or immunomodulatory drug-based therapies, chemotherapy) on survival and extent of clinical response, including progression-free survival and overall survival (OS). Progression-free survival and OS were assessed by the Kaplan-Meier method, and survival distributions were compared by log-rank test.

RESULTS

In our cohort of 46 PPCL patients, the median age at the time of diagnosis was 54 years. Overall response rate was 54% (25/46). The median (95% confidence interval) progression-free survival time was 6 (0-12.5) months, and OS time was 14 (4.6-23.4) months. The OS time was significantly longer in patients treated with bortezomib-based versus non-bortezomib-based therapies (median [95% confidence interval], 19 [9-28.9] vs. 5 [4-24] months; P = .019).

CONCLUSION

This large single-center study of PPCL supports the use of bortezomib-based therapies as frontline treatment in PPCL patients.

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.

MYC amplification on double minute chromosomes in plasma cell leukemia with double IGH/CCND1 fusion genes

In multiple myeloma (MM), MYC rearrangements that result in increased MYC expression are associated with an aggressive form of MM and adverse outcome. However, the consequences of MYC amplification in MM remain unclear. Here, we describe an unusual case of plasma cell leukemia (PCL) harboring MYC amplification on double minute chromosomes (dmin). A 79-year-old woman was initially diagnosed as having BJP-κ type MM with bone lesions. After seven months, the disease progressed to secondary PCL: leukocytes 49.1 × 10⁹/L with 77% plasma cells showing lymphoplasmacytic appearance. The bone marrow was infiltrated with 76% plasma cells immunophenotypically positive for CD38 and negative for CD45, CD19, CD20, and CD56. The karyotype by G-banding and spectral karyotyping was 48,XX,der(14)t(11;14)(q13;q32),+der(14)t(14;19)(q32;q13.1),+18,6~95dmin[15]/46,XX[5]. Fluorescence in situ hybridization detected multiple MYC signals on dmin and double IGH/CCND1 fusion signals on der(14)t(11;14) and der(14)t(14;19). Most plasma cells were diffusely and strongly positive for MYC and CCND1 by immunohistochemistry. The patient died of progressive disease after one week. MYC amplification led to high expression of MYC and rapid disease progression, indicating its clinical significance in the pathogenesis of MM/PCL. MYC amplification on dmin may be a very rare genetic event closely associated with the progression to PCL and coexistence of IGH/CCND1 fusions.

[Successful treatment with lenalidomide-containing regimen of plasma cell leukemia accompanied by meningeal involvement]

The central nervous system (CNS) is rarely involved in plasma cell neoplasms (PCN), especially in patients with advanced disease, harboring poor prognostic chromosomal abnormalities. The prognosis after development of CNS is poor, with a median survival of 2-6 months. Here, we present a 56-year-old woman with isolated CNS relapse of plasma cell leukemia who was admitted to our hospital with back pain, thigh pain, and dysuria. Morphological examination of the cerebrospinal fluid (CSF) confirmed the presence of relapsed plasma cell leukemia, whereas active myeloma lesions were not detectable outside the CNS. Her symptoms did not improve with high doses of methotrexate or intrathecal chemotherapy. However, one cycle of combination therapy with lenalidomide and dexamethasone led to the improvement in clinical symptoms, with complete response seen in the CSF morphology. After 13 cycles, she developed a hematological relapse but maintained complete response in the CSF. The efficacy of lenalidomide in CSF PCN was sporadically reported, and the CNS penetrance of lenalidomide was demonstrated in animal models; however, its efficacy in CNS PCN has not been established. The current case supports the efficacy of combination therapy with lenalidomide as a new therapeutic strategy for CNS PCN.

Pixantrone demonstrates significant in vitro activity against multiple myeloma and plasma cell leukemia

Treatment results for multiple myeloma and plasma cell leukemia have considerably improved, but cure remains elusive and establishing new therapeutic approaches constitutes a major unmet clinical need. We analyzed the anti-myeloma properties of the aza-anthracenedione pixantrone which has been successfully used in a phase III study for the treatment of patients with aggressive non-Hodgkin's lymphoma as monotherapy as well as in combination regimes in vitro and in an adapted in vivo model (ex ovo chicken chorioallantoic membrane (CAM) assay). Pixantrone significantly inhibited proliferation and metabolic activity of all investigated myeloma cell lines. Importantly, anti-myeloma effects were more pronounced in tumor cell lines than in stromal cells, mesenchymal stem cells, and peripheral blood mononuclear cells of healthy controls. Apoptosis of myeloma cell lines was observed only after a 7-day incubation period, indicating a fast cytostatic and a slower cytotoxic effect of this drug. Pixantrone reduced the viability of primary plasma cells of patients and induced downregulation of myeloma-cell growth in the CAM assay. Additionally, we demonstrate in vitro synergism between pixantrone and the histone deacetylase inhibitor panobinostat with respect to its anti-proliferative features. From these data, we conclude that systematic investigations of the clinical usefulness of pixantrone in the framework of controlled clinical trials are clearly indicated (e.g., in penta-refractory patients).

Plasma Cell Leukemia: Definition, Presentation, and Treatment

Purpose of Review

We discuss current topics on the definition of plasma cell leukemia and the distinction between plasma cell leukemia and multiple myeloma. Moreover, we review the latest literature on how to treat plasma cell leukemia.

Recent Findings

Plasma cell leukemia is clinically and genetically distinct from multiple myeloma. Plasma cell leukemia is defined by the observation in blood of more than 20% clonal plasma cells by differential count of the leucocytes or by counting more than 2 × 10⁹ per liter circulating clonal plasma cells. However, patients with lower levels of circulating plasma cells have the same adverse prognosis, which challenges the disease definition. Survival has improved after implementation of high-dose chemotherapy with stem-cell support, bortezomib, and lenalidomide in the treatment; yet, the prognosis remains poor. The results of allo-transplants have been disappointing.

Summary

The diagnostic criteria of PCL are currently discussed in the international myeloma community. Despite some improvement in survival, the prognosis remains adverse. New, more targeted treatment modalities, including immunotherapies, will hopefully improve the outcome in the near future.

Rare and unusual case of anti-factor XI antibodies in patient with plasma cell leukemia

Background

The acquired inhibitors of coagulation have been observed in very rare cases of monoclonal gammopathies. We report a very rare case of anti-factor XI antibodies in patient with plasma cell leukemia (PCL).

Case presentation

This is a 59-year-old male patient without pathological history, admitted to the nephrology department for management of renal insufficiency and anemia syndrome. The history and physical examination revealed stigmata of hemorrhagic syndrome including hemothorax and hemoptysis. The hemostasis assessment showed an isolated prolonged activated partial thromboplastin time (APTT) with APTT ratio = 2.0.The index of circulating anticoagulant (37.2%) revealed the presence of circulating anticoagulants. The normalized dilute Russell viper venom time ratio of 0.99 has highlighted the absence of lupus anticoagulants. The coagulation factors assay objectified the decrease of the factor XI activity corrected by the addition of the control plasma confirming the presence of anti-factor XI autoantibodies. In addition, the blood count showed bicytopenia with non-regenerative normocytic normochromic anemia and thrombocytopenia. The blood smear demonstrated a plasma cell count of 49% (2842/mm3) evoking PCL. The bone marrow was invaded up to 90% by dystrophic plasma cells. The biochemical assessment suggested downstream renal and electrolyte disturbances from exuberant light chain production with abnormalities including hyperuricemia, hypercalcemia, elevated lactate dehydrogenase, non nephrotic-range proteinuria and high level of C reactive protein. The serum protein electrophoresis showed the presence of a monoclonal peak. The serum immunofixation test detects the presence of monoclonal free lambda light chains. He was treated with velcade, thalidomide and dexamethasone. The patient died after 2 weeks despite treatment.

Conclusion

Both PCL and anti-factor XI inhibitors are two very rare entities. To the best of our knowledge, this is the first reported case of a factor XI inhibitor arising in the setting of PCL. Factor inhibitors should be suspected in patients whose monoclonal gammopathies are accompanied by bleeding manifestations.

Clinical Resolution of Red Cell Aplasia Associated del 17p Multiple Myeloma, When Treated With Bortezomib and Dexamethasone

Red cell aplasia has been rarely described in association with multiple myeloma. We present a case of a 79-year-old female, who was initially diagnosed with iron deficiency anemia, which did not improve with iron supplementation and required blood transfusions. Bone marrow biopsy showed red cell aplasia associated with kappa light chain multiple myeloma with 14.8% plasma cells. Further tests showed 0.35 g/dL M protein, and kappa/lambda ratio was 131.84. Cytogenetic showed deletion 13q, deletion 17p, loss of 1p and gain of chromosome 5. Multiple myeloma directed treatment with bortezomib and dexamethasone was initiated. Patient had clinical resolution of anemia and did not require further blood transfusions. This is an intriguing case of red cell aplasia associated with poor risk multiple myeloma (del 17p), which showed clinical improvement in anemia with bortezomib-based therapy. This case highlights the role of clonal plasma cells proliferation in the pathogenesis of red cell aplasia as myeloma directed treatment helped patient to become transfusion independent.

[Primary plasma cell leukemia: about 3 cases]

La leucémie à plasmocytes est une hémopathie maligne rare définie par la présence de plus de 20 % de plasmocytes de la formule leucocytaire ou un nombre de plasmocytes circulants supérieur à 2 × 10⁹/L (2G/L). Elle peut être primitive, dans 60% des cas, et se manifeste d'emblée sur un mode leucémique ou secondaire, dans 40% des cas, compliquant un myélome multiple connu. Vu la rareté de cette affection, seuls quelques cas ont été rapportés dans la littérature. Elle est caractérisée par son agressivité et son mauvais pronostic. A travers 03 cas diagnostiqués au laboratoire d'hématologie de l'hôpital militaire Mohammed V les auteurs présentent les particularités cliniques, biologiques et pronostic de cette affection.

Plasma Cell Leukemia Presenting as a Chest Wall Mass: A Case Report

Plasma cell leukemia (PCL) is an uncommon neoplasm of plasma cells, with an aggressive clinical course and poor outcome, even with current standard of care. It can occur either de novo (primary PCL) or as a progression of multiple myeloma (MM). This disease has unique diagnostic criteria but certain genetic markers and clinical features may overlap with MM. Due to the low prevalence of PCL, guidelines on its management are extrapolated from the management of MM and based on small retrospective studies and cases reports/series. We present an interesting case of PCL in a middle-aged African-American male, who was diagnosed incidentally after chest wall imaging for an unrelated complaint. The diagnostic approach, management and outcomes of PCL are discussed.

Plasma cell leukemia in North India: retrospective analysis of a distinct clinicohematological entity from a tertiary care center and review of literature

Background

Plasma cell leukemia (PCL) is a rare and aggressive plasma cell neoplasm. In PCL, clonal plasma cells comprise ≥20% of the peripheral blood (PB) leukocytes and/or the absolute clonal PB plasma cell count is ≥2×10⁹/L. Primary PCL (PPCL) originates de novo, whereas, secondary PCL (SPCL) evolves from pre-existing multiple myeloma.

Methods

Clinicohematological features, immunophenotypic profile, and survival of PCL patients were analyzed retrospectively.

Results

Between January 2007 and December 2014, ten PPCL and four SPCL patients were investigated (8 PPCLs and 3 SPCLs had complete clinical data). All were North Indians, sharing common geography and ethnicity. Our cohort showed less frequent renal failure, more frequent hepatomegaly, and non-secretory type disease. In contrast to western literature, flow cytometric immunophenotyping of our cohort revealed altered expression of CD138 (67%), CD56 (33%), and CD20 (0%). With novel therapeutic agents, these PPCL patients had a median overall survival of 15 months.

Conclusion

We highlight that our PPCL patients from North India had distinct clinicohematological and immunophenotypic profiles. The significance of our findings must be tested in a larger patient cohort and must be supported by molecular and cytogenetic investigations to unmask possible significant effects on pathogenesis.

Synchronous Thyroid Involvement in Plasma Cell Leukemia Masquerading as Hashimoto's Thyroiditis: Role of Ancillary Cytology Techniques in Diagnostic Workup

Neoplastic plasma cell involvement of thyroid is an uncommon condition, and it may involve thyroid in multiple myeloma or solitary plasmacytoma. Its clinical and pathological features are not well understood. We present a rare case of synchronous thyroid involvement in plasma cell leukemia presenting as thyroid nodule with primary hypothyroidism. Simultaneous cytology, immunocytochemistry, FISH analysis with 13q14.3 and TP53 on cytology smears and haematology workup were performed to diagnose and to understand disease pathobiology with poor outcome.

Plasma cell leukemia: Clinicopathologic, immunophenotypic and cytogenetic characteristics of 4 cases

Plasma cell leukemia (PCL) is a rare hematologic malignancy with very poor outcome. It is defined by the presence of >2 × 10(9)/L plasma cells or >20% plasmacytosis of the differential white cell count in the peripheral blood. Primary PCL is first diagnosed in the leukemic phase, while secondary PCL corresponds to the leukemic transformation of a previously diagnosed multiple myeloma (MM). The incidence of PCL ranges between 2-4% of patients with MM and 0.9% of patients with acute leukemia. In this case series, we describe the clinicopathologic, immunophenotypic, and cytogenetic findings of four patients diagnosed with PCL within a ten-year period (2002-2012) at King Faisal Specialist Hospital and Research Centre (General Organization), Riyadh, Saudi Arabia.

Primary plasma cell leukaemia with unusual presentations: a case series

We present here three cases of plasma cell dyscrasias; first case presenting as primary plasma cell leukemia showing unusual morphology and aberrant expression of myeloid markers; the second case presenting as plasma cell leukaemia with atypical plasma cells in peripheral blood and the third case presenting as myelomatous pleural effusion after treatment for myeloma.

A case of CD138-/CD19+/CD4+ IgD plasma cell leukemia

Background: Plasma cell leukemia (PCL) is an uncommon and aggressive disease caused by the clonal proliferation of atypical plasma cells with phenotypical abnormalities similar to those seen in multiple myeloma (MM), although at different rates. Here we report a case of IgD PCL with a very unusual CD138-/CD19+/CD4+ phenotype Methods: Peripheral blood and bone marrow samples from a 37 year old patient afflicted by an aggressive plasma cell dyscrasia were examined and analyzed by conventional morphology, flow cytometry and immunohistochemistry. Results: Analysis of peripheral blood fulfilled criteria for PCL (more than 20% and more than 2x10e9 cells/L). However, flow cytometry and immunohistochemistry phenotyping revealed that the cells were CD138-/CD38+/CD19+/CD4+/CD56-/CD117- Conclusion: PCL is diagnosed on peripheral blood smear. Immunophenotyping is a tool that can be helpful in diagnosing difficult cases but its atypical findings should not prevent the appropriate PCL diagnosis in clinically and morphologically unquestionable cases. © 2014 Clinical Cytometry Society.

Biclonal light chain gammopathy with aberrant CD33 expression in secondary plasma cell leukemia

Plasma cell leukemia is a rare neoplastic proliferation of circulating plasma cells. Clonal proliferations of plasma cells, such as in plasma cell leukemia or plasma cell myeloma, are typically characterized by production of a monoclonal heavy and/or light chain immunoglobulin. We present a case of a secondary plasma cell leukemia arising from plasma cell myeloma with dual expression of lambda and kappa light chains along with aberrant expression of CD33, CD20, and dim CD56. This case emphasizes the importance of recognizing aberrant immunophenotypes in plasma cell leukemias and represents the first reported case of biclonal light chain expression in a secondary plasma cell leukemia.

Clinico-pathological spectrum of primary plasma cell leukemia diagnosed at a tertiary care centre in South India over 5 year period

Plasma cell leukemia (PCL) represents a rare and aggressive form of plasma cell dyscrasia which can be primary (pPCL) or secondary (sPCL). It is diagnosed based on absolute plasma cell count of more than 2.0 × 10(9)/l or a relative proportion of greater than 20% of the peripheral blood leukocyte count. Although pPCL and sPCL share several clinical features, important differences exist. Patients with pPCL are younger; often have extra osseous organ involvement (liver, spleen and other extramedullary sites), increased frequency of renal failure, fast declining performance status and rapid progression to the terminal stage. Patients with sPCL have advanced bone disease. Presented in this article is India data of a short series of five cases of PCL diagnosed at a tertiary care centre from south India over last 5 years. All cases were de novo and had varied spectrum of presentation and so were not suspected to be plasma cell dyscrasia clinically. Detailed hemato-pathological evaluation clinched the diagnosis in all the cases.

Cell cycle genes co-expression in multiple myeloma and plasma cell leukemia

The objective of this study was to describe co-expression correlations of cell cycle regulatory genes in multiple myeloma (MM) and plasma cell leukemia (PCL). Our results highlight the presence of dynamic equilibrium between co-expression of activator and inhibitor gene sets. Moreover inhibitor set is more sensitive to the activator changes, not vice versa. We have shown that CDKN2A expression is associated with short-term survival in newly diagnosed MM patients (survival was 30.3 ± 3.9 months for 'low' expressed and 7.5 ± 5.6 months for 'high' expressed group, p<0.0001). Moreover low-expression CDKN2A group showed time-to-progression benefit in newly diagnosed patients (remission was 20.8 ± 3.6 months for 'low' and 8.4 ± 2.7 months for 'high' expressed group, p<0.0001) as well as in whole studied cohort of MM patients (remission was 20.8 ± 2.8 months for 'low' and 9.8 ± 1.1 months for 'high' expressed group, p<0.0001). The overexpression of inhibitors can be explained as a compensatory reaction to growing "oncogenic stress".

Clinical features and outcomes of plasma cell leukemia: a single-institution experience in the era of novel agents

Plasma cell leukemia (PCL) is a rare hematologic malignancy with aggressive clinical and biologic features. Data regarding its prognosis with the use of the novel agents, i.e., the immunomodulatory drugs thalidomide and lenalidomide, and the proteasome inhibitor bortezomib, are limited. We retrospectively reviewed clinical outcomes, response to therapy, and survival of 17 patients seen at the Penn State Hershey Cancer Institute since the availability of novel agents (2006–2011). Twelve patients had primary PCL (pPCL), and 5 secondary PCL (sPCL). PCL was associated with aggressive clinicobiological features, such as high-risk cytogenetics, elevated serum beta-2-microglobulin and lactate dehydrogenase, International Staging System stage III, and rapid relapse after therapy. With the use of thalidomide, lenalidomide, and bortezomib in 53%, 53%, and 88% patients, respectively, median overall survival (OS) was 18 months in the whole group (95% confidence interval, 11–21 months), and 21 and 4 months in pPCL and sPCL, respectively (P=0.015). OS was inferior to that of 313 consecutive patients with multiple myeloma (MM) treated in the same period, even when compared with a subset of 47 MM with high-risk cytogenetics. Although our data are limited by the small sample size, we conclude that novel agents may modestly improve survival in patients with PCL, when compared to historical controls. Novel therapies do not seem to overcome the negative prognosis of PCL as compared with MM.

Primary non-secretory plasma cell leukemia with atypical morphology - a case report

Only one case of primary non-secretory plasma cell leukemia with atypical morphology has been reported thus far. Here we report another such case of plasma cell leukemia diagnosed on fl ow cytometry, as morphological heterogeneity and lack of monoclonal immunoglobulins in both serum and urine, made it difficult to come to a conclusive diagnosis based purely on morphology.