PLASMA CELL DYSCRASIAS Overview.....pptx

Presentation on Plasma cell dyscrasias

1. PLASMA CELL DYSCRASIAS PRESENTED BY: DR. GREESHMA GOPINATH JR, DEPT. OF PATHOLOGY AIIMS PATNA MODERATED BY: DR. SURABHI ASST.PROFESSOR, DEPT.OF PATHOLOGY AIIMS PATNA

2. PLASMA CELLS & ITS DEVELOPMENT Plasma cells are terminally differentiated B-lineage cells that secrete Ig as a protective antibody response Normal stages of B cell development; adapted from Quick reference handbook-Natasha Rekhtman

3. IMMUNOGLOBULIN(Ig) Constitute 20-25 per cent of total serum proteins. Five classes: IgG, IgA, lgM, IgD and IgE. Four polypeptide chains Two identical heavy chains (H) Two identical light chains (L) Heavy chains are of five types: Light chains: kappa & lambda In humans, 60 percent of L chains are kappa and 40 percent are lambda. Normal serum kappa/serum lambda ratio=0.26 to 1.65

4. PLASMA CELL DYSCRASIAS A plasma cell dyscrasia or monoclonal gammopathy is defined as a proliferation of a single clone of plasma cells , either neoplastic or non-neoplastic , associated with the production of a monoclonal serum protein that can be usually measured in the serum, urine, or both. MGUS PLASMA CELL MYELOMA INCLUDING THE FOLLOWING VARIANTS Smouldering multiple myeloma Non-secretory myeloma Plasma cell leukemia PLASMACYTOMA Solitary plasmacytoma of bone Extramedullary plasmacytoma MONOCLONAL IMMUNOGLOBULIN DEPOSITION DISEASE Primary amyloidosis Systemic light and heavy chain deposition disease PLASMA CELL NEOPLASMS WITH ASSOCIATED PARANEOPLASTIC SYNDROMES POEMS syndrome TEMPI syndrome

5. MONOCLONAL GAMMOPATHY OF UNDETERMINED SIGNIFICANCE (MGUS) Asymptomatic, pre-malignant clonal plasma cell proliferative disorder. Three types: IgM MGUS Non-IgM MGUS Light chain MGUS

6. Non IgM MGUS 80-85% of MGUS M>F, >70 years of age Diagnostic Criteria: All 3 must be met Serum M protein (non-lgM) concentration <30 g/L Clonal bone marrow plasma cells< 10% Absence of end-organ damage; e.g. hypercalcaemia, renal insufficiency, anaemia, and bone lesions (CRAB) and amyloidosis attributable to the plasma cell proliferative disorder M protein: IgG(60%)> IgA(15%)> Biclonal (3%)> IgD(1%) , IgE(1%)

7. Flowcytometry: Shows two population of cells

8. IgM MGUS Serum lgM monoclonal protein concentration < 30 g/L Bone marrow lymphoplasmacytic infiltration of <10% No evidence of anaemia, constitutional symptoms, hyperviscosity, lymphadenopathy, hepatosplenomegaly, or other end-organ damage that can be attributed to the underlying lymphoproliferative disorder. Flow cytometry: Non specific phenotype – CD19+, CD20+, CD10-, CD5-, CD103-, CD56- 15% cases of MGUS M>F >70 years of age Diagnostic criteria: All three must be met

9. Light Chain MGUS Diagnostic criteria: Abnormal free light chain ratio ( < 0.26 or> 1.65) Increased level of the involved free light chain No immunoglobulin heavy chain expression on immunofixation electrophoresis Urinary M protein < 500 mg/24 hours Clonal plasma cells < 10% Absence of end-organ damage (CRAB) and amyloidosis

10. TYPES RISK OF PROGRESSION Non-IgM MGUS 1% per year risk of progression to plasma cell myeloma, AL amyloidosis , or related disorder IgM MGUS 1.5% per year risk of progression to Lymphoplasmacytic lymphoma/ Waldenstrom’s macroglobulinemia or other B cell neoplasms, primary amyloidosis. Rarely to PCM. Light chain MGUS Risk of progression to light chain myeloma and AL amyloidosis . Rate of progression not defined

11. MONOCLONAL GAMMOPATHY OF RENAL SIGNIFICANCE (MGRS) Includes all kidney disorders caused by a monoclonal protein (M-protein) secreted by a small plasma cell clone or other B-cell clones in patients who do not meet the diagnostic criteria for multiple myeloma or other B-cell malignancies. MGRS includes: Light chain (AL), heavy chain (AH), and heavy and light chain (AHL) amyloidosis Monoclonal immunoglobulin deposition disease (MIDD) Proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) Cryoglobulinaemia-associated glomerulonephritis (CGG) Monoclonal gammopathy-associated thrombotic microangiopathy (TMA) Monoclonal gammopathy-associated C3 glomerulopathy (C3GP) Light chain proximal tubulopathy (LCPT) Crystal-storing histiocytosis (CSH) Immunotactoid glomerulopathy (ITG)

12. Spectrum of monoclonal gammopathy of renal significance by localization Source - Monoclonal gammopathy of renal significance (MGRS): histopathologic classification, diagnostic workup, and therapeutic options - K. Amaador et. al

13. PLASMA CELL MYELOMA Bone marrow based multifocal neoplastic proliferation of plasma cells characterized by a clinical pentad: anaemia a monoclonal protein in the serum or urine or both bone lesions and/ or bone pain hypercalcemia renal insufficiency 10-15% of haematopoietic neoplasms 90% cases occur >50 years(median age 70 years), M>F.

14. DIAGNOSTIC CRITERIA FOR PLASMA CELL MYELOMA Clonal bone marrow plasma cell percentage >=10% or biopsy-proven plasmacytoma and >= 1 of the following myeloma-defining events End-organ damage attributable to the plasma cell proliferative disorder Hypercalcaemia: serum calcium > 1 mg/dL higher than the upper limit of normal or > 11 mg/dL Renal insufficiency: creatinine clearance<40ml/min or serum creatinine> 2 mg /dL Anaemia: a haemoglobin value of> 2g/dL below the lower limit of normal or a haemoglobin value< 10g/dL Bone lesions: >= 1 osteolytic lesion on skeletal radiography, CT, or PET /CT >= 1 of the following biomarkers of malignancy Clonal bone marrow plasma cell percentage >= 60% An involved-to-uninvolved serum free light chain ratio >=100 > 1 focal lesion on MRI

15. PATHOGENESIS INITIATING EVENT: IGH translocation Involves Cyclin D(CCND) family – results in cell progression MAF transcription factor expression affected Hyper diploidy of chromosome 3,5,7,9,11,15 MYC Locus rearrangements Deletion 13q Interaction of myeloma cells with bone marrow microenvironment Initiation of plasma cell proliferation in microenvironment of bone marrow MGUS Occurs Myeloma cell growth and survival increased The myeloma cells hijack the normal hematopoietic niche to aid the growth & proliferation of tumor cells Multiple Myeloma

16. MM cells + Mesenchymal stem cells Produce excess of MMP-1,2,8,9,13 Main role of MMP-9 Secretes VEGF-A Neo angiogenesis Spread of MM MM cells+ CD138 on their surface(heparan sulfate proteoglycan) Binds to Type 1 collagen Induces expression of MMP-1 Promotes tumor invasion, bone resorption & angiogenesis Resorption of ECM Plasma cell leukemia

17. Myeloma cells secrete macrophage inflammatory protein-1alpha (MIP1alpha) and MIP1ß MIP1alpha binds to C-chemokine receptor 1 (CCR1) and CCR5 while MIP1ß binds to CCR5 and CCR8 to induce osteoclast formation Osteoclasts secrete IL6 - stimulate proliferation and growth of myeloma cells & other osteoclasts BMSC produce RANKL which binds with RANK receptor & stimulates osteoclastic activation and differentiation Bone lysis Osteoblasts produce OPG(Osteoprotegerin) OPG competes with RANKL for RANK Myeloma cells inhibit osteoblast production & activation Increase in ratio of RANKL/OPG – Activation of osteoclast

18. CLINICAL FEATURES Weakness, fatigue Pallor Bone pains Pathological fractures Recurrent infections Elevated ESR Hypercalcemia Bence Jones proteinuria Renal failure Amyloidosis

19. LABORATORY FINDINGS BLOOD Normocytic normochromic, macrocytes less often Rouleaux formation Background of smear basophilic Leucoerythroblastic picture in some Coagulopathy Later stages- pancytopenia

20. BIOCHEMICAL TESTS Liver function tests: - Total protein: increased. Serum alkaline phosphatase: is normal or slightly increased Kidney function tests : -Serum creatinine: is raised in the presence of renal insufficiency -Serum calcium: hypercalcemia SERUM ELECTROPHORESIS Initial step in the identification of abnormal proteins A localized dense band with sharp margins in the γ region indicates M band In about 80% of patients with monoclonal gammopathies, M band will be detected.

21. SERUM ELECTROPHORESIS IN A NORMAL PERSON SERUM ELECTROPHORESIS IN A PATIENT OF MULTIPLE MYELOMA; M BAND PRSENT

22. IMMUNOFIXATION ELECTROPHORESIS Gold standard for identification of nature of M protein In this technique, serum proteins are separated by electrophoresis in a gel and monospecific antiserum (IgG, IgM, IgA, κ or λ light chains) is applied directly over the surface of the gel. Immunoprecipitation band develops in the gel between corresponding protein antigen and the monospecific antiserum.

23. SERUM FREE LIGHT CHAIN(SFLC) ASSAY Sensitive marker than electrophoresis & immunofixation for detection of M protein Used as a substitute for 24 hr urine immunofixation Measured by immunonephelometry Clonal plasma cells produce>100mg/L of SFLC & affected SFLC/unaffected SFLC >100 Free light chain assay measures amount of free kappa to lambda chain ratio (normal – 0.26 to 1.65) Useful in cases of Non-secretory myeloma Light chain myeloma MGUS Amyloidosis Smouldering MM

24. QUANTITATIVE IMMUNOGLOBULIN ASSAY The quantitation of monoclonal and other immunoglobulins is necessary to assess the disease severity and follow response to treatment M protein is considered measurable if it is >=1g/dL in the serum & or >=200mg/day in urine. The height of the peak on serum protein electrophoresis is directly proportional to the amount of M protein Exact quantification can be done by nephelometry

25. BONE MARROW Hypercellular to normocellular Myeloid series, erythroid series & megakaryocytes morphology is normal Marrow infiltration by myeloma cells Monoclonal plasma cells varies between 10% to 90%

26. MATURE TYPE: Cytoplasm – abundant deeply basophilic with a perinuclear clear area/hof representing golgi zone Nucleus- Eccentrically placed nucleus with coarse chromatin and no nucleoli. IMMATURE TYPE: Size larger Light blue abundant cytoplasm, hof can be present Centrally/ eccentrically placed nucleus, diffuse open chromatin, 1 or 2 prominent nucleoli Pleomorphism may be seen

27. PLASMABLASTIC TYPE Large cells with central nuclei having high N/C ratio Fine reticular chromatin & prominent nucleoli No perinuclear hof Plasmablastic myeloma- >2% marrow cells are plasmablasts PLEOMORPHIC/ANAPLASTIC TYPE: Marked pleomorphism Frequent multinucleated and bizzare cells Nuclear lobulation Mitotic figures seen

28. OTHER VARIANTS : Small cell variant : Shows a lymphoplasmacytic appearance, with a narrow rim of basophilic cytoplasm and the occasional perinuclear hof Taken from: Plasma cell myeloma with lymphoplasmacytic morphology and cyclin D1 expression, an uncommon variant Daniel A. Hale, MD, and John R. Krause, MD Fig: Scattered lymphoplasmacytic cells with occasional small perinuclear hof and eccentric nuclei with rare definitive plasma cell Higher magnification shows small plasma cells with high N:C ratio Biopsy shows numerous lymphoplasmacytic cells CD 138+ Cyclin D1+

29. PLASMA CELL INCLUSIONS The cytoplasm of myeloma cells has abundant endoplasmic reticulum, which may contain condensed or crystallized cytoplasmic Ig producing a variety of morphological findings Mott cells (grape cells or morula forms) plasma cells filled with dense spherical immunoglobulin inclusions these inclusions are colorless, pink, or blue Russell bodies: Intracytoplasmic hyaline inclusions Appear as cherry-red refractive round bodies

30. DUTCHER BODY: Intranuclear inclusions FLAME CELLS: Peripheral rim of cytoplasm shows a pinkish hue Glycogen rich fibrils Commonly seen in IgA myelomas

31. BONE MARROW BIOPSY: Is of importance in Asymptomatic plasma cell myeloma Plasma cells <10% in aspirate BMB shows foci of plasma cells in marrow Myeloma cases with hypocellular marrow with inadequate aspirate Myeloma associated fibrosis (prognosis worse) Bone marrow necrosis in PCM Congo red staining in case of amyloidosis associated with PCM Proper assessment of hematopoietic reserve in non involved marrow Different infiltration pattern of myeloma cells can be understood

32. Interstitial infiltration Focal/nodular Diffuse/packed Paratrabecular

33. IMMUNOPHENOTYPING BY FLOWCYTOMETRY Useful for diagnosis and monitoring of PCM MRD monitoring: FCM is a sensitive method, detects even one myeloma cell among 10,000 total marrow cells. NORMAL PLASMA CELLS NEOPLASTIC PLASMA CELLS Polytypic cytoplasmic Igs with kappa:lambda in range of 1:1 to 2:1 Monotypic cytoplasmic Ig and lacks surface Ig CD 38 and CD 138+ CD138 +(brighter) CD38+ (dimmer) CD19 + CD19- CD45+ CD45+ in early plasma cells and CD45- in mature ones CD56- & CD20- CD56 + & CD20+(~20% cases) Additional findings CD27 & CD 81 + CD117, CD200,CD28 - Aberrant expression in ~90% cases CD117, CD200 , CD28+ CD10+ Myeloid and monocytic antigens CD27- & CD81-

34. Blue – Normal plasma cells Brown - Neoplastic plasma cells Wang H-W, and Lin P. Flow Cytometric Immunophenotypic Analysis in the Diagnosis and Prognostication of Plasma Cell Neoplasms. Cytometry Part B 2019; 96B: 338–350 Adapted from:

35. IMMUNOHISTOCHEMISTRY On marrow biopsies, IHC is the method of choice for clonality and enumeration of plasma cells. Plasma cell number – CD38/CD138 For characterizing clonal nature & distinguishing from reactive plasmacytosis – Anti-kappa & Anti-lambda. CD138 IHC most a sensitive method to assess volume pre-treatment or posttreatment PCM Presence of microaggregates of plasma cells(>10 in non-perivascular location) in a post remission BMB indicates early relapse

36. Cyclin D1 positive cases carry good prognosis CD138 positivity (membrane positivity) Clonality – Anti-kappa (cytoplasmic positivity)

37. CYTOGENETICS Primary molecular cytogenetic classification of multiple myeloma (Multiple myeloma: 2020 update on diagnosis, risk-stratification and management)

38. Cytogenetic abnormalities on clinical course and prognosis in multiple myeloma STANDARD RISK HIGH RISK Trisomies Standard risk MM Median OS- 7 to 10 years t(4;14) (p16;q32) Median OS 5 y t(11;14) (q13;q32) Standard risk MM Median OS- 7 to 10 years t(14;16) (q32;q23) Median OS 5 y Associated with high levels of FLC t(6;14) (p21;q32) Standard-risk MM Median OS 7-10 years t(14;20) (q32;q11) Median OS 5 y Normal Good prognosis Probably reflecting low tumor burden Median OS >7-10 y Del(17p) & Gain(1q21) Median OS 5 y Trisomies plus any one of the IgH translocations May ameliorate adverse prognosis conferred by high risk IgH translocations, and del 17p

39. Revised international staging system for myeloma ( Multiple myeloma: 2020 update on diagnosis, risk-stratification and management)

40. VARIANTS OF PLASMA CELL MYELOMA SMOLDERING PLASMA CELL MYELOMA Represents progression from MGUS with a greater burden of plasma cells in the bone marrow(>10%) & a higher risk of transformation to MM. Diagnostic criteria(IMWG 2014): Both criteria must be met Serum M protein (lgG or lgA) >=30 g/L or urinary M protein >= 500 mg/24hrs and/or clonal bone marrow plasma cell percentage of 10-60%. Absence of myeloma-defining events or amyloidosis Light chain SPCM: 10-60% bone marrow clonal plasma cells & urinary light chain M protein excretion of >=0.5mg/24hrs.

41. Risk factors for early progression to symptomatic PCM: The presence of both > 10% bone marrow plasma cells and > 30 g/L M protein Detection of bone lesions by MRI High percentage of bone marrow plasma cells with an aberrant immunophenotype Abnormal serum free light chain ratio High-risk gene expression profile High plasma cell proliferation rate, and circulating plasma cells.

42. 2. NON SECRETORY MYELOMA ~ 1% cases of PCM Absence of an M protein by serum & urine immunofixation electrophoresis 85% cases show cytoplasmic M protein by IHC indicating impaired secretion of Ig 15% cases are non-producer myelomas(no cytoplasmic Ig) Elevated serum free light chain &/or an abnormal free light chain ratio by immunofixation electrophoresis – oligosecretory myeloma

43. 3. PLASMA CELL LEUKEMIA PCM in which clonal plasma cells constitute > 20% of total leukocytes in the blood or the absolute count is >2000/ul The bone marrow is usually extensively and diffusely infiltrated. Primary PCL- A de novo disease with no evidence of PCM & Secondary PCL – leukemic transformation of PCM Extramedullary involvement like in liver, spleen, spinal fluid, body cavity effusions seen A higher proportion of cases of light chain- only, lgE, and lgD myelomas present as PCL compared with lgG or lgA myelomas. PCL – CD20+ & CD56- (~80% cases) Patients with PCL have aggressive disease , poor response to therapy, and a relatively short survival.

44. Single localized tumors consisting of monoclonal plasma cells No clinical features of plasma cell myeloma (PCM) No physical or radiographical evidence of additional plasma cell tumor Two types: Solitary plasmacytoma of bone (1-2% of plasma cell neoplasms) Extraosseous(extramedullary) plasmacytoma (1% of plasma cell neoplasms) PLASMACYTOMA

45. SOLITARY PLASMACYTOMA A localized tumor consisting of monoclonal plasma cells with no clinical features of PCM M/c site: Thoracic vertebrae>lumbar/cervical>ribs>skull>pelvis>femur>humerus> clavicle IMWG diagnostic criteria for solitary plasmacytoma:

46. Solitary plasmacytoma of rib

47. EXTRAOSSEOUS PLASMACYTOMA Localized plasma cell neoplasms that arise in tissues other than bone. M/C site: mucous membrane of upper airway passages. Other sites: gastrointestinal tract, lymph nodes, bladder, breasts, thyroid, testes, parotid glands, skin, and CNS M protein present in 20% cases in low levels Morphology: Usually mature plasma cells seen. Immunophenotype: Plasma cell markers & cytoplasmic Ig light chains are positive CD56 positivity less common, weak Cyclin D1 negative

48. Molecular alterations: Same as PCM except that t(11;14) translocation and MYC rearrangement are absent. Good outcome, progression to PCM in 15% cases. D/D: Extraosseous infiltrates of plasma cell myeloma MALT lymphoma with plasma cell differentiation Lymphoplasmacytic lymphoma Plasmablastic lymphoma

49. EXTRAOSSEOUS PLASMACYTOMA OF TESTIS Diffuse sheets of immature plasma cells

50. Extraosseous infiltrates of PCM Plasmablastic lymphoma Primary extraosseous plasmacytoma Clinical features & predisposing factors Usually in PCM Relapse after treatment HIV infection Iatrogenic immunosuppression Elderly immunocompetent patients No known predisposing factors Location Any site Predominantly extranodal, GIT, oral cavity, skin, LNs 80% in head & neck region,mostly extranodal Osteolytic lesions Common, disseminated Rare Rare local infiltration(skull) M protein >95% Rare 20%, low level Bone marrow involvement Yes Rare No manifested involvement Morphology Plasmablastic/ plasmacytic Immunoblastic/plasmablastic, occasionally plasmacytic component Usually plasmacytic

51. Extraosseous infiltrates of PCM Plasmablastic lymphoma Primary extraosseous plasmacytoma Immunophenotype PC markers + Cyt Ig light chains + CD 56 + PC markers + Cyt Ig light chains + CD 56 + (10 to 30 %) B cell markers negative PC markers + Cyt Ig light chains + CD 56 weak + Cyclin D1 - ve Molecular alterations MYC rearrangement frequent with PB morphology PCM cytogenetics 50% MYC rearrangement PCM type translocations absent MYC rearrangement absent t(11;14) EBV infection Absent 50 – 75% Rare Outcome Poor Poor Good , progression to PCM in 15% WHO classification of tumors of hematopoietic & lymphoid tissue

52. MONOCLONAL IMMUNOGLOBULIN DEPOSITION DISEASE Closely related disorders characterized by visceral and soft tissue deposition of aberrant lg , resulting in compromised organ function Underlying disorder: a plasma cell neoplasm or rarely a lymphoplasmacytic neoplasm Two major categories: Primary amyloidosis Light chain and heavy chain deposition diseases.

53. PRIMARY AMYLOIDOSIS Disorder in which the monoclonal plasma cells secrete intact or fragments of abnormal Ig light chains that deposit in various tissues and form a beta-pleated sheet structure (amyloid light chain). M>F >40 years of age Diagnostic biopsy site: Abdominal subcutaneous fat pad or bone marrow M protein detected in serum: IgG> only light chain(Lambda>kappa)> IgA> IgM> IgD Gross: Amyloid has dense waxy appearance On H&E: Amyloid is a pink, amorphous, waxy-looking substance with a characteristic cracking artefact . Macrophages and foreign-body giant cells may be found around deposits.

54. Bone marrow showing extensive involvement by amyloidosis Pulmonary blood vessel with amyloid deposition, showing Congo red staining Congo red stains amyloid pink to red by standard light microscopy, and under polarized light produces a characteristic apple-green birefringence

55. LIGHT CHAIN & HEAVY CHAIN DEPOSITION DISEASES Plasma cell or (rarely) lymphoplasmacytic neoplasms that secrete an abnormal light or (less often) heavy chain, or both , which deposit in tissues, causing organ dysfunction. They do not form amyloid beta-pleated sheets, bind Congo red stain, or contain an amyloid P component. 3 disorders: Light chain deposition disease (LCDD), Heavy chain deposition disease (HCDD) Light and heavy chain deposition disease (LHCDD) M>F 30 – 80 Years Deposition: m/c kidney, others- liver, heart. blood vessels, nerves Detectable M protein seen in 85% cases

56. HCDD – m/c IgG3/ IgG1 type & LCDD – m/c kappa chain Microscopy: Deposition m/c in renal biopsies- seen as amorphous eosinophilic material non-amyloid, non-fibrillary. No congo red staining. LCDD can present as nodular sclerosing GN IF: hallmark of LCDD - prominent, smooth, ribbon-like linear peritubular deposits of monotypic lg along the outer edge of the tubular basement membrane EM: deposits are non-fibrillary, powdery, and electron dense, with an absence of the beta-pleated sheet structure by X-ray diffraction

57. PLASMA CELL NEOPLASMS WITH ASSOCIATED PARANEOPLASTIC SYNDROME POEMS SYNDROME TEMPI SYNDROME P- Polyneuropathy O- Organomegaly E- Endocrinopathy M- Monoclonal gammopathy S- Skin changes T- Telangiectasias E- Elevated erythropoietin & erythrocytosis M- Monoclonal gammopathy P- Perinephric fluid collection I- Intrapulmonary shunting Neoplastic plasma cells are IgG or IgA type & are lambda restricted Mostly IgG kappa VEGF levels are elevated markedly Normal VEGF levels Characteristic BM finding is a single/multiple osteosclerotic plasmacytoma No specific morphologic findings BM clonal plasma cells are <5% but can be >50% also Usually <10%

58. HEAVY CHAIN DISEASES ALPHA (M/C) GAMMA MU Definition A/k/a Immunoproliferative small intestinal disease, Mediterranean lymphoma. a variant of extra nodal marginal zone MALToma Small B cell neoplasm with plasmacytic differentiation B cell neoplasm resembling CLL Age 2 nd to 3 rd decade 60 years Adults( median age- 60) Cause Chronic intestinal infections- C.jejuni Localization GIT + Mesenteric lymph nodes LN, GIT, BM, Waldeyer ring, liver, spleen, blood Spleen, liver, BM, blood Clinical features Malabsorption, diarrhoea , pain abdomen, hypocalcemia, fever Systemic symptoms+ Autoimmune manifestations+ generalized lymphadenopathy Hepatosplenomegaly+ absence of lymphadenopathy

59. ALPHA GAMMA MU Microscopy Lamina propria infiltrated by plasma cells & small lymphocytes, villous atrophy can be seen. Marginal zone B cells +/- LN: polymorphous proliferation of admixed lymphocytes, plasmacytoid lymphocytes, plasma cells, immunoblasts, histiocytes & eosinophils BM: Vacuolated plasma cells + small round lymphocytes Immunophenotyping Marginal zone B cells- CD20+ & CD10,CD5 – Plasma cells – CD20-CD138+ Monoclonal cytoplasmic alpha chains without light chains CD79a +, CD5 & CD10- CD138 + on plasma cells CD20+ on lymphocytes Kappa & lambda - monoclonal cytoplasmic mu heavy chain positive CD20,CD79a + CD10 & CD5 -

60. BMA shows plasma cells with prominent cytoplasmic vacuoles along with small mature lymphocytes – Mu HCD LP shows dense inflammatory infiltrates Infiltrates composed of atypical plasma cells IgA positive on IHC IgM negativ e Alpha HCD Polymorphous population of cells in LN – Gamma HCD Taken from: The Heavy Chain Diseases: Clinical and Pathologic Features Giada Bianchi, MD, Kenneth C. Anderson, MD, Nancy Lee Harris, MD, Aliyah R. Sohani, MD

61. WALDENSTROM MACROGLOBULINEMIA A malignancy of mature B cells characterized by a monoclonal IgM in the serum and the presence of lymphoplasmacytic lymphoma (LPL) in the bone marrow. Classical clinical findings include anemia, organomegaly, lymphadenopathy, and hyperviscosity. WM cells are characterized by the surface expression of CD19, CD20, CD22 & are light chain restricted , and commonly express CD79a. CD10 & CD23 negative CD138 expressed in plasma cells Lymphoplasmacytic morphology of the clonal cells of WM

62. RECENT CASES

63. CASE 1 56 year/F H/o backpain since last 4 years Advised for CBC & other biochemical tests Radiological investigations done- revealed lytic lesions in skull and L4 vertebra Bone marrow aspiration studies and serum electrophoresis and immunofixation was advised DIAGNOSIS: Plasma Cell Myeloma

64. CONGO RED UNDER POLARIZED LIGHT

65. 65/F, back pain for last 3 months Routine laboratory test done Radiological investigations were done Bone marrow aspiration, biopsy from lytic lesions & other biochemical tests were advised CASE 2

66. CD138 Kappa Lambda NON-SECRETORY MYELOMA

67. CASE 3: 5/M presented with right sided hard palate mass Routine investigations and biopsy from the mass was advised. Biopsy report: Poorly differentiated malignancy Immunohistochemistry done: CD138+, CD45 -, CD20-, Ki67 high CD138 Bone marrow aspiration & biopsy done – Trilineage hematopoiesis with no atypical lymphoid infiltration. PLASMABLASTIC LYMPHOMA

68. REFERENCES: WHO classification of tumors of hematopoietic and lymphoid tissues, revised 4 th edition. Wintrobe’s Clinical Hematology , 13 th Edition Bone marrow pathology- Barbara J Bain Quick Reference Handbook for Surgical Pathologists - Natasha Rekhtman Wang H-W, and Lin P. Flow Cytometric Immunophenotypic Analysis in the Diagnosis and Prognostication of Plasma Cell Neoplasms. Cytometry Part B 2019; 96B: 338–350 The Longevity of the Humoral Immune Response: Survival of Long-lived Plasma Cells - Pei Xiong Liew Multiple myeloma: 2020 update on diagnosis, risk-stratification and management Monoclonal gammopathy of renal significance (MGRS): histopathologic classification, diagnostic workup, and therapeutic options- K. Amaador et. al The Heavy Chain Diseases: Clinical and Pathologic Features - Giada Bianchi, MD, Kenneth C. Anderson, MD, Nancy Lee Harris, MD, Aliyah R. Sohani , MD