Nonsecretory plasma cell myeloma--becoming even more rare with serum free light-chain assay: a brief review

Oligosecretory myeloma with gastrointestinal tract involvement: an unusual presentation and literature review

A woman in her 70s with vague gastrointestinal (GI) symptoms and unintentional weight loss was referred to endoscopy clinic for investigation and consideration of GI malignancy. CT of the thorax, abdomen and pelvis showed a suspicious mass in the oesophago-gastric junction with a lytic lesion on S1-S2 sacrum. A subsequent upper GI endoscopy revealed two raised, ulcerated tumours on the lesser curvature of the stomach. By the time an MRI of the whole spine was done which revealed multiple metastases involving thoracic, lumbar and sacral skeleton, she had developed leg weakness and paraesthesias, consistent with the imaging findings. A positron emission tomography/CT scan further confirmed the above findings. The initial working diagnosis was primary GI tumour with bony metastases. However, she was later referred to the haematology team after the immunohistochemistry of the tumour showed that it was of a plasma cell origin (CD138 positive) associated with lambda light chain deposits. Serum-free light chain showed a raised lambda light chain of 272 mg/L and kappa light chain of 11.3 mg/L and involved/uninvolved light chain ratio of 24. Bone marrow biopsy confirmed a plasma cell myeloma with moderate disease burden. Monoclonal lambda chains were demonstrated on immunofixation but negative on serum protein electrophoresis and hence a diagnosis of oligosecretory myeloma with GI involvement was made. Subsequent management involved physiotherapy, pain management and chemotherapy, where this woman was commenced on Velcade (generically known as bortezomib), thalidomide and dexamethasone and she continued to experience clinical and biochemical improvement.

Immune subtraction for improved resolution in serum protein immunofixation electrophoresis and antibody isotype determination in a patient with autoantibody

Heavy chain isotypes of low level monoclonal immunoglobulins are sometimes obscured in serum immunofixation electrophoresis (SIFE) by a heavy background of polyclonal immunoglobulins. However, accurate determination of the heavy chain isotype is essential for a complete diagnosis, as isotype determination of autoantibodies may have relevance in determining therapeutic procedures. Immune subtraction (IS) was employed in a patient with neuropathy and GD1a autoantibody. IS allowed identification of the cognate heavy chain related to a lambda light chain restriction noted on initial SIFE as well as isotype determination of the autoantibody.

Antisera specific to individual heavy and light chains were used for depletion of specific immunoglobulin types. Depletion of kappa light chain associated immunoglobulins allowed unequivocal determination of the isotype of lambda light chain-associated low level monoclonal band to be IgG Lambda. Selective depletion of kappa, lambda, gamma and mu heavy chain immunoglobulins was employed to determine IgG Kappa isotype of the auto-antibody.

Oligosecretory multiple myeloma: a devastating presentation of a difficult diagnosis

A 57-year-old man with lumbar pain and fever was diagnosed with spondylodiscitis. Afterward, he acquired full paraplegia. Image studies showed a mass extending from D9 to the vertebral canal, plus numerous adjacent osteolytic lesions. Serum immunoelectrophoresis was normal, bone marrow had 0.5% of monoclonal plasmocytes, but D9's biopsy found a plasmacytoma. Despite bone marrow aspiration results, skeleton osteolytic lesions made multiple myeloma (MM) a more plausible diagnosis, later confirmed by the biopsy. The absence of classical MM findings, alongside a medullary compression syndrome, suggested an oligosecretory MM, which was proved by an altered FLC essay. This delayed diagnosis, with multiple diagnostic misguiding leads, also presents rare IgA and lambda chains production and normal levels of uninvolved immunoglobulins. Oligosecretory MM can lead to an inaccurate and delayed diagnosis, with devastating consequences to patient's morbidity and mortality. Therefore, FLC essay is essential in early assessment of potential MM patients.

Serum and Urine Protein Electrophoresis and Serum-Free Light Chain Assays in the Diagnosis and Monitoring of Monoclonal Gammopathies

BACKGROUND

Laboratory methods for diagnosis and monitoring of monoclonal gammopathies have evolved to include serum and urine protein electrophoresis, immunofixation electrophoresis, capillary zone electrophoresis, and immunosubtraction, serum-free light chain assay, mass spectrometry, and newly described QUIET.

CONTENT

This review presents a critical appraisal of the test methods and reporting practices for the findings generated by the tests for monoclonal gammopathies. Recommendations for desirable practices to optimize test selection and provide value-added reports are presented. The shortcomings of the serum-free light chain assay are highlighted, and new assays for measuring monoclonal serum free light chains are addressed.

SUMMARY

The various assays for screening, diagnosis, and monitoring of monoclonal gammopathies should be used in an algorithmic approach to avoid unnecessary testing. Reporting of the test results should be tailored to the clinical context of each individual patient to add value. Caution is urged in the interpretation of results of serum-free light chain assay, kappa/lambda ratio, and myeloma defining conditions. The distortions in serum-free light chain assay and development of oligoclonal bands in patients' status post hematopoietic stem cell transplants is emphasized and the need to note the location of original monoclonal Ig is stressed. The need for developing criteria that consider the differences in the biology of kappa and lambda light chain associated lesions is stressed. A new method of measuring monoclonal serum-free light chains is introduced. Reference is also made to a newly defined entity of light chain predominant intact immunoglobulin monoclonal gammopathy. The utility of urine testing in the diagnosis and monitoring of light chain only lesions is emphasized.

Oligosecretory Myeloma With Amyloidosis and Alopecia

Amyloidosis is a systemic illness characterized by the extracellular deposition of abnormal proteins in body tissues and organs. In addition to renal involvement, amyloidosis can also present with a variety of skin manifestations, though rarely with alopecia. Sixteen cases of alopecia secondary to systemic amyloidosis are reported. There is one reported case that presented with alopecia universalis. We report a case of a 68-year-old woman presenting with alopecia universalis, rapid decline in kidney function, and nephrotic syndrome who was found to have multiple myeloma-associated AL amyloidosis (immunoglobulin light chain). Her serological workup including serum electrophoresis was negative and she underwent renal biopsy. Pathology revealed eosinophilic material within the mesangium that was Congo-red positive, had apple-green birefringence under polarized light, and ultramicroscopically appeared as fibrillary material. Subsequent bone marrow examination showed a diffuse increase in plasma cells with atypia indicating plasma cell neoplasm. This case underlines several interesting aspects of multiple myeloma and the way it may present with amyloidosis. The lack of monoclonal spike on electrophoresis yet positive light chain analysis deserves special attention by clinicians to avoid a missed diagnosis. The extensive skin involvement also raises several questions regarding the pathologic mechanisms of alopecia in a patient with amyloidosis.

Is it solitary plasmacytoma or nonsecretory myeloma? A must-be-solved dilemma?

Presentation of multiple myeloma with bone lesions is common. It is vital that differentiation between nonsecretory multiple myeloma and plasmocytoma be done and that each disorder be treated accordingly. In this paper, we present a patient with nonsecretory multiple myeloma, who suffered from distal humerus fracture with severe bone destruction, renal failure, hypercalcemia and anemia.

Plasma cell morphology in multiple myeloma and related disorders

Normal and reactive plasma cells (PC) are easy to ascertain on human bone marrow films, due to their small mature-appearing nucleus and large cytoplasm, the latter usually deep blue after Giemsa staining. Cytoplasm is filled with long strands of rough endoplasmic reticulum and one large Golgi apparatus (paranuclear hof), demonstrating that PC are dedicated mainly to protein synthesis and excretion (immunoglobulin). Deregulation of the genome may induce clonal expansion of one PC that will lead to immunoglobulin overproduction and eventually to one among the so-called PC neoplasms. In multiple myeloma (MM), the number of PC is over 10% in most patients studied. Changes in the morphology of myeloma PC may be inconspicuous as compared to normal PC (30-50% patients). In other instances PC show one or several morphological changes. One is related to low amount of cytoplasm, defining lymphoplasmacytoid myeloma (10-15% patients). In other cases (40-50% patients), named immature myeloma cases, nuclear-cytoplasmic asynchrony is observed: presence of one nucleolus, finely dispersed chromatin and/or irregular nuclear contour contrast with a still large and blue (mature) cytoplasm. A peculiar morphological change, corresponding to the presence of very immature PC named plasmablasts, is observed in 10-15% cases. Several prognostic morphological classifications have been published, as mature myeloma is related to favorable outcome and immature myeloma, peculiarly plasmablastic myeloma, is related to dismal prognosis. However, such classifications are no longer included in current prognostic schemes. Changes related to the nucleus are very rare in monoclonal gammopathy of unknown significance (MGUS). In contrast, anomalies related to the cytoplasm of PC, including color (flaming cells), round inclusions (Mott cells, Russell bodies), Auer rod-like or crystalline inclusions, are reported in myeloma cases as well as in MGUS and at times in reactive disorders. They do not correspond to malignant changes of PC but are related to abnormal synthesis, trafficking, or excretion of the immunoglobulin that is stored in excess within the cytoplasm. Occurrence of crystalline inclusions within PC may be the first anomaly leading to the diagnosis of adult Fanconi syndrome. After a historical perspective, the authors report on the various morphological aspects of PC that may occur in multiple myeloma and related disorders, and discuss about their clinical and pathophysiological significance. Today, morphological identification and accurate determination of % PC within bone marrow remain ancillary criteria for the diagnosis of MM and help for the diagnosis of rare renal disorders.

Characteristics and Results of the Treatment of Multiple Myeloma in the Subject under the Age of 65 at the University Hospital of Yopougon in Abidjan, Côte d'Ivoire

We retrospectively studied 30 cases of multiple myeloma in patients under the age of 65, diagnosed from 1991 to 2005 in the clinical hematology department of the University Hospital of Yopougon that is a hospital incidence of 2.9 cases/year. The age of patients ranged from 34 to 64 years, with a mean age of 49 years and a sex ratio of 1.73. The professional activity was variable with 3% of radiographers and 10% of farmers. Clinically, the dominant sign was bone pain in 83% of cases. Myeloma was secretory in 93% of cases. It was Ig G-type in 86%, kappa-type in 66% of cases. 86% of patients were anemic, 20% had creatinine >20 mg/L, and 10% had serum calcium >120 mg/L. Geodes were found in 80% of cases. 53% were at stage III of DURIE and SALMON. Complications were infectious (33%), renal (20%), and hemorrhagic (7%). Chemotherapy regimens were VAD (10%), VMCP (30%), and VMCP/VBAP (60%) with 47% of partial responses, 33% of stable disease, and 7% of very good quality partial responses. The outcome developed towards death in 37% and causes of death were renal in 46% of cases. The median survival was only 5.1 months.

Serial measurement of free light chain detects poor response to therapy early in three patients with multiple myeloma who have measurable M-proteins

Free light chain (FLC) assays are important in the diagnosis and monitoring of patients with multiple myeloma (MM). Serum FLC concentrations also correlate with disease course in the majority of MM patients and have been incorporated into the new response criteria. Although baseline values of FLC are prognostic in newly diagnosed MM, serial measurement of serum FLC does not appear to be of greater value in patients who have measurable M-proteins by electrophoresis. We examined the kinetics of serum FLC in six patients with newly diagnosed MM during treatment with high-dose dexamethasone (HD-DEX) and bortezomib and dexamethasone. In some cases, the involved serum FLC increased in the latter part of each chemotherapy cycle before the start of the next cycle, especially in HD-DEX, suggesting that the response to these agents may be insufficient for induction therapy for MM. Earlier disease assessment by serum FLC assays may be of value in detecting poorly responding patients who require alternative forms of therapy.

Serum B-cell maturation antigen is elevated in multiple myeloma and correlates with disease status and survival

Although TNFRSF17 (also designated as B-cell maturation antigen (BCMA)) is expressed on tumour cells in B-cell malignancies, it has not been found in serum. The present study found that BCMA concentrations were higher in the supernatants of cultured bone marrow mononuclear cells from multiple myeloma (MM) patients than in healthy subjects. Serum BCMA levels were measured in samples from MM patients (n = 209), monoclonal gammopathy of undetermined significance (MGUS) individuals (n = 23) and age-matched controls (n = 40). BCMA was detected in the serum of untreated MM patients (n = 50) and levels were higher than in MGUS patients (P = 0·0157) and healthy subjects (P < 0·0001). Serum BCMA levels were higher among patients with progressive disease (n = 80) compared to those with responsive disease (n = 79; P = 0·0038). Among all MM patients, overall survival was shorter among patients whose serum BCMA levels were above the median (P = 0·001). We also demonstrated that sera from mice with human MM xenografts contained human BCMA, and levels correlated with the change in tumour volume in response to melphalan or cyclophosphamide with bortezomib. These results suggest that serum BCMA levels may be a new biomarker for monitoring disease status and overall survival of MM patients.

Oligo-secretory myeloma in a patient with ankylosing spondylitis

Non-secretory myeloma is a plasma cell dyscrasia characterized by the absence of serum and urinary monoclonal immunoglobulins on electrophoretic tests. Because of the lack of monoclonal protein, the identification of the disease is more difficult than for secretory myelomas. The coexistence of ankylosing spondylitis and multiple myeloma has been reported occasionally. We report a rare case of oligo-secretory myeloma coexistent with ankylosing spondylitis.

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.

Comparable outcomes in nonsecretory and secretory multiple myeloma after autologous stem cell transplantation

Nonsecretory myeloma (NSM) accounts for <5% of cases of multiple myeloma (MM). The outcome of these patients following autologous stem cell transplantation (ASCT) has not been evaluated in clinical trials. We compared the outcomes after ASCT for patients with NSM reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) between 1989 and 2003, to a matched group of 438 patients (4 controls for each patient) with secretory myeloma (SM). The patients were matched using propensity scores calculated using age, Durie-Salmon stage, sensitivity to pretransplant therapy, time from diagnosis to transplant, and year of transplant. Disease characteristics were similar in both groups at diagnosis and at transplant except higher risk of anemia, hypoalbuminemia, and marrow plasmacytosis (in SM) and plasmacytoma (more in NSM). Cumulative incidence of treatment-related mortality (TRM), relapse, progression-free survival (PFS), and overall survival (OS) were similar between the groups. In multivariate analysis, based on a Cox model stratified on matched pairs and adjusted for covariates not considered in the propensity score, we found no difference in outcome between the NSM and SM groups. In this large cohort of patients undergoing ASCT, we found no difference in outcomes of patients with NSM compared to those with SM.

Investigative Tools for Diagnosis and Management

Recent advances in genomics and proteomics have advanced our understanding of myeloma pathogenesis, recognized novel mediators of disease process, and identified new therapeutic targets. These developments have provided newer diagnostic tools for myeloma, improved monitoring of the disease status and allowed for molecular classification of the disease. The recent advances in investigative techniques that have helped refine the diagnostic work up in myeloma includes use of serum free light chains, especially in oligosecretory myeloma, patients with renal disease and with amyloidosis; use of MRI and PET scan in diagnosis and managing bone disease; and use of cytogenetics and fluorescent in situ hybridization (FISH) technique to determine prognosis. Newer risk stratification protocols have included international staging systems as well as FISH-detected chromosomal changes, specifically t(4;14), t(14;16), and del 17p. These improved predictive risk stratification models are guiding treatment algorithms. As the novel therapies are able to attain complete responses in a significant number of patients, the response categories are also being redefined. Immunophenotypic identification of clonal plasma cells, inclusion of free light chain response and molecular markers of disease now allow us to define stringent complete responses. Recent studies show the increasing importance of attaining complete remission to extended overall survival. The ongoing oncogenomic studies including high-throughput expression profiling, high-density single nucleotide polymorphism (SNP)–arrays and array based comparative hybridization (aCGH) have been utilized to not only understand myeloma pathobiology, but for gene discovery, identification of biomarkers, and delineation of patient subgroups to incorporate them into therapeutic strategies and to eventually provide optimal individualized therapy.