Nghiên cứu phân loại u lympho ác tính không hodgkin tế bào b theo WHO 2008 TT TIENG ANH

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH HANOI MEDICAL UNIVERSITY PHAM VAN TUYEN A STUDY ON CLASSIFICATION OF B-CELL NONHODGKIN LYMPHOMA ACCORDING TO WHO 2008 Major : Pathology and Forengic Pathology Code : 62720105 SUMMARY OF DOCTORAL THESIS HA NOI - 2021 THE SCIENTIFIC WORK WAS COMPLETED AT HANOI MEDICAL UNIVERSITY Academic supervisors: Assoc Prof Dr Le Dinh Roanh Reviewer 1: Assoc Prof Dr Ngo Thu Thoa Reviewer 2: Prof Dr Bach Quoc Khanh Reviewer 3: Assoc Prof Dr Tạ Van To The thesis will be defended in front of the school-level doctoral thesis examination committee held at Hanoi Medical University Time of organization: ……hours….date……month… 2021 The thesis can be found at: Vietnam National Library Hanoi Medical University Library LIST OF THE PUBLISHED RESEARCHES RALATED TO THE THESIS Pham Van Tuyen, Doan Minh Khuy, Nguyen Van Hung, Le Dinh Roanh (2017) Immunohistochemical characteristics of Non-Hodgkin Diffuse large B cell lymphoma Vietnamese Medical Journal, vol: 461, Special issue: 160-166 Pham Van Tuyen, Le Van Ky, Nguyen Cong Trung, Nguyen Thi Ngan (2017) A case report: Leukaemic non-nodal mantle cell lymphoma Ho Chi Minh City Journal of Medicine, vol:21, issue:4: 122-126 Pham Van Tuyen, Doan Minh Khuy, Nguyen Van Hung, Le Dinh Roanh (2018) The WHO 2008 classification of NonHodgkin B cell lymphomas Vietnamese Medical Journal, vol: 471, Thematic issue: 128-133 INTRODUCTION Non-Hodgkin lymphoma is one of the most common cancers in Vietnam and many countries around the world, accounts for about 80% of all lymphomas In 2012, the World Health Organization (WHO) reported that the incidence of non-Hodgkin lymphoma was 2.7%, the mortality rate was 2.4%, and there were 385,741 new cases annually in the world According to GLOBOCAN (2012), there were nearly 2,700 newly reported cases of lymphoma in Vietnam every year In the 1990s, the diagnosis of non-Hodgkin lymphoma was mainly based on morphology and histopathological features Since the beginning of the 21st century, the classification of non-Hodgkin lymphoma has been revised several times These changes resulted from not only a deeper understanding of disease pathogenesis derived from advances in molecular biology and immunology but also a better understanding of clinical behavior In 2001, on basis of the previous classifications, WHO published a new classification of lymphomas which had been widely studied and applied in Vietnam In 2008, WHO again introduced a new classification of lymphomas as well as non-Hodgkin lymphomas This new classification added some entities in the histopathological subtype and updated many immunohistochemical markers, especially diagnostic markers of Tcell non-Hodgkin lymphoma Recently, a new version of WHO classification had been released in 2016 It is true that an accurate diagnosis of histopathology, biological characteristics and clinical stage plays an important role in patient’s treatment and prognosis There are three main treatments of nonHodgkin lymphoma includes chemotherapy (alone or combined), radiation therapy or both In Vietnam, many regimens have been applied such as: COP, CHOP, MACOP, m-BACOP, ProMACE-CytaBOM A correct and timely diagnosis helps clinicians making the right decisions in treatment and improving patient survival as well as reduce healthcare cost Due to all above reasons, we carried out a study on the topic: "A Study on classification of B-cell non-Hodgkin lymphoma according to WHO 2008" The goals of the study: Determination of histopathological type of B-cell non-Hodgkin lymphoma according to the 2008 WHO classification Relationship between clinical features and histopathology of B-cell non-Hodgkin lymphoma *New scientific contributions: Non-Hodgkin lymphoma comprises a group of heterogeneous diseases originating from lymphocytes Since 2100s, several classifications of lymphoma have been proposed causing many difficulties for both pathologists and clinicians in the diagnosis, treatment and patient's prognosis In order to unify terminology and create a common voice in lymphoma diagnosis and treatment, the World Health Organization released a classification of lymphoma in 2001 This classification was continually revised and updated in 2008 and 2016 which resulted from new understanding about histological morphology, immunohistochemistry, molecular biology and clinical features Study’s practical values: It is undeniable that an accurate diagnosis of histopathology plays an essential role in optimal treating and prognosing patient Therefore, the application of WHO classification in diagnosing lymphomas will help clinicians to properly treat specific types of lymphoma and also provide an overview of common lymphoma types in Vietnam, especially B-cell lymphoma which is the most common type of lymphoma Thesis’s structure The layout of the thesis includes 113 pages with pages for introduction, 38-paged overview, 13 pages for objects and research methods, 28-paged results, 32-paged discussion, 2-paged conclusions and 1-paged recommendations It also contains 44 tables, pictures, chart CHAPTER OVERVIEW 1.1 History of Lymphoma Classification - In 1966, Rappaport proposed a classification based on morphology (lymphocyte, histiocytic and mixed type), cell differentiation (well-differentiated, poorly differentiated) and pathological pattern (diffuse, nodular) - 1970, Lukes and Collins based on morphology and immunomarker analysis to classify non-Hodgkin lymphoma into various cell lineages - 1975, Kiel classification by using cytologic features grouped lymphomas into low grade and high grade - In 1982, the US National Cancer Institute released Working Formulation for Clinical Use This classification divided nonHodgkin lymphoma into groups of low-grade lymphoma, intermediate-grade lymphoma, and high-grade lymphoma -In 1994, the REAL classification based on morphology, immunology, cytogenetics and molecular biology determined the type of non-Hodgkin lymphoma -In 2001, WHO introduced a classification of hematopoietic and lymphoid tissue tumors focused on morphology, immunohistochemistry, molecular genetics, and clinical features -In 2008, WHO updated its classification and introduced new pathological entities and variants basing on new understanding of pathogenesis and molecular biology 1.2 The 2008 WHO classifications of Non-Hodgkin B cell lymphoma Table 1.5 WHO 2008 classification of non-Hodgkin lymphoma Precursor lymphoid neoplasms B lymphoblastic leukaemia/lymphoma Mature B-cell neoplasms Chronic lymphocytic leukaemia/small lymphocytic lymphoma B-cell prolymphocytic leukaemia Splenic B-cell marginal zone lymphoma Hairy cell leukaemia Lymphoplasmacytic lymphoma Waldenstrom macroblobulinemia Heavy chain diseases Plasma cell myeloma Solitary plasmacytoma of bone Extraosseous plasmacytoma Extra-nodal marginal zone lymphoma of mucosaassociated lymphoid tissue (MALT lymphoma) Nodal marginal zone lymphoma Follicular lymphoma Primary cutaneous follicle center lymphoma Mantle cell lymphoma Diffuse large B-cell lymphoma (DLBCL), NOS T-cell/histiocyte rich large B-cell lymphoma Primary DLBCL of CNS Primary cutaneous DLBCL, leg type EBV positive DLBCL of the elderly DLBCL associated with chronic inflammation Lymphomatoid granulomatosis Primary mediastinal (thymic) large B-cell lymphoma Intravascular large B-cell lymphoma ALK positive large B-cell lymphoma Plasmablastic lymphoma Large B-cell lymphoma arising in HHV8associated multicentric Castleman disease Primary effusion lymphoma Burkitt lymphoma B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma Precursor lymphoid neoplasms T lymphoblastic leukaemia/lymphoma Mature T-cell and NK-cell neoplasms T-cell prolymphocytic leukaemia T-cell large granular lymphocytic leukaemia Chronic lymphoproliferative disorder of NK-cells Aggressive NK cell leukaemia Systemic EBV positive T-cell lymphoproliferative disease of childhood Hydroa vacciniforme-like lymphoma Adult T-cell leukaemia/lymphoma Extranodal NK/T cell lymphoma, nasal type Enteropathy-associated T-cell lymphoma Hepatosplenic T-cell lymphoma Subcutaneous panniculitis-like T-cell lymphoma Mycosis fungoides Serazy syndrome Primary cutaneous CD30 positive T-cell lymphoproliferative disorders Lymphomatoid papulosis Primary cutaneous anaplastic large cell lymphoma Primary cutaneous gamma-delta T-cell lymphoma Primary cutaneous CD8 positive aggressive epidermotropic cytotoxic Tcell lymphoma Primary cutaneous CD4 positive small/medium T-cell lymphoma Peripheral T-cell lymphoma, NOS Angioimmunoblastic T-cell lymphoma Anaplastic large cell lymphoma, ALK positive Anaplastic large cell lymphoma, ALK negatve 1.2.1 Basic principle of immunohistochemistry panel in the diagnosis of B-cell non-Hodgkin lymphoma 1.2.1.1 B cell markers The CD20 marker is expressed on B cells from pre-B cell stage in the bone marrow until the plasma cell differentiation stage The CD79a marker has the widest spectrum of expression from the early B cells in the bone marrow to the plasma cell differentiation stage The PAX5 marker is also expressed from early B cells in the bone marrow and ended before plasma cell differentiation phase Therefore, most of the histopathological types of non-Hodgkin B-cell lymphoma have a high expression rate with CD20 However, in some histopathological type consists of abnormal myeloma cell populations (such as chronic lymphocytic leukemia/small lymphocytic lymphoma) or in patients treated with rituximab, the CD20 expression may be weakly positive or negative, so it is necessary to add additional markers CD79a and PAX5 1.2.2 Immunohistochemistry in the group of small cell B-cell lymphomas 1.2.2.1 Role of CD5 and CD10 in diagnosis small B-cell lymphoma CD5 positive/CD10 negative is commonly expressed in mantle cell lymphoma and small lymphocytic lymphoma CD5 negative/CD10 positive is commonly expressed in follicular lymphoma or acute leukemia/B lymphoblastic lymphoma The negative expression pattern for both CD5 and CD10 is observed in marginal zone lymphoma, plasma cell lymphoma and hair leukemia Very rare type of non-Hodgkin small B cell lymphoma are CD5 and CD10 positive (0.05 Table 3.8 The expression of BCL2 and BCL6 or C-MYC markers in DLBCL Percentage Expression n BCL6/BCL2 and C-MYC 17 22,1 Co-expression markers 5,2 No expression or one of markers 56 72,7 Total 77 100 (%) 15 In 77 cases of diffuse large B-cell lymphoma with adequate staining of markers: BCL2, BCL6, c-MYC in our study, there were 17 cases with co-expression of markers BCL2/BCL6 and c-MYC; cases expressed all markers; accounted for 22.1% and 5.2% respectively 3.2.4 Immunohistochemistry expressions in non-Hodgkin small B cell lymphoma Table 3.9 Immunohistochemistry expressions in non-Hodgkin small B cell lymphoma Small B cell lymphoma IHC FL MZL CLL/SLL MCL LPL markers Quantity (%) Quantity (%) Quantity (%) Quantity (%) QUantity (%) CD3 0/25 0,0 0/36 0,0 0/5 0,0 0/22 0,0 0/2 0,0 CD20 25/25 100,0 34/36 94,4 5/5 100,0 22/22 100,0 2/2 100,0 CD79a 25/25 100,0 36/36 100,0 4/5 80,0 22/22 100,0 2/2 100,0 CD5 1/25 4,0 0/36 0,0 5/5 100,0 19/22 86,4 0/2 0,0 CD23 1/25 4,0 0/36 0,0 5/5 100,0 0/22 0,0 0/2 0,0 CD10 21/25 84,0 0/36 0,0 0/5 0,0 1/22 4,5 0/2 0,0 BCL6 16/25 64,0 1/36 2,7 0/5 0,0 0/22 0,0 0/2 0,0 BCL2 21/25 84,0 29/36 80,1 0/5 0,0 21/22 95,5 2/2 100,0 CyclinD1 0/14 0,0 0/36 0,0 0/5 0,0 21/22 95,5 0/2 0,0 The markers for B-cell lineage (CD20, CD79a) were expressed in almost all cases of small cell lymphoma In MZL, there were cases with negative expression of CD20 marker, however, both cases expressed CD79a marker In MCL and CLL/SLL, there was a high rate of CD5 positive expression, 86.4% and 100%, respectively However, cases MZL 16 negative were for CD5 FL and MZL were mostly negative for CD5, but case of FL showed positive with this marker CLL/SLL was totally positive with CD23 Additional, case FL that was positive for CD23, its morphologic type was FL with diffuse structure The BCL2 marker had a high expression rate in the small B-cell lymphoma group, with the rate ranges from 84.0 to 100.0% (except for CLL/SLL type) The CyclinD1 marker was not expressed in other histopathological types except MCL Percentage of positive CyclinD1 expression in MCL was 95.5% There was case with negative CyclinD1 expression, in this case staining with additional SOX11 marker showed positive results and confirmed the diagnosis The CD10 and BCL6 markers showed little expression in all histopathological types except FL In the FL subtype, the rate of expression with CD10 and BCL6 were 84% and 64%, respectively Table 3.10 Average of Ki67 index within Non-Hodgkin Small/ Medium-Large B cell lymphoma Ki67 Morphologic type Non-Hodgkin Medium-Large B cell lymphoma Non-Hodgkin Small B cell lymphoma Quantity Average 202 73,8±12,7 90 29,4±18,1 p 0,00 In medium and large cell B cell lymphoma, the average Ki67 index was 73.8±12.7 Small B cell lymphoma had an average Ki67 index of 29.4±18.1 There was a statistically significant difference in the mean Ki67 index between the groups of non-Hodgkin small and medium-large B cell lymphoma, with p0.05 Table 3.13 Clinical stage and Ki67 index Ki67 n Median p Stage Stage I, II 52 64,8±23,2 (early) 0,509 Stage III, IV 28 23,1±4,0 (advanced) There was no difference between the mean value of Ki67 index between the early and advanced stages with p>0.05 18 CHAPTER DISSCUSSION 4.1 Characteristics of age and gender distribution The average age of Non-Hodgkin B cell lymphoma patients in the study was 57.9±14.6 years old, in which the youngest patient was years old, the oldest patient was 89 years old The study results showed that the disease was found in all age groups and the age group accounted for the highest proportion was from 50-59 years old, about 29.2% Non-Hodgkin B cell lymphoma was more commonly encountered in adults > 50 years old There was no difference in the incidence of the disease between both genders This result is consistent with the finding of Le Dinh Hoe (1996) His research showed that the age group with the highest incidence is from 50-59 years old 4.2 Distribution of tumor site The study showed that most of Non-Hodgkin B cell lymphoma appeared in lymph nodes, accounted for 47.9% Non-nodal site was less common, but Non-Hodgkin B cell lymphoma could occur in all tissue and organs in the body Tumors were more common in organs which were rich in lymphoid tissue such as the gastrointestinal tract, nasopharynx The most common extra-nodal site was the gastrointestinal tract (16.8%), followed by the nasopharyngeal region (10.9%) This result was similar to Do Anh Tu (2012) study, in which the rate of Non-Hodgkin B cell lymphoma in lymph nodes was 47.7% Our results were lower than results of Le Dinh Hoe (1996) and Nguyen Tuyet Mai (2013), which were 75 and 89.1%, respectively In the gastrointestinal tract, B-cell lymphoma were mostly detected in the stomach (accounted for 42.8%), the second site is the jejunum and ileum (made up 28.5%); esophagus and appendix were rarely detected it This result is consistent with Koch P (2001) study in which the stomach was the most common site of B-cell lymphoma in the gastrointestinal tract with the rate of 74.8% 19 4.3 Characteristics of histopathological distribution according to the classification of the World Health Organization 2008 Among the B-cell lymphoma cases of the study, the histopathology results showed that large and medium-cell lymphomas predominated with 69.2% According to the WHO 2008 classification, the histopathological type comprised the highest proportion was diffuse large B-cell lymphoma (67.4%); the second ones was marginal lymphoma (in the lymph nodes and outside the lymph nodes) and accounted for 12.3%; followed by follicular lymphoma accounted for 8.6% In diffuse large B-cell lymphoma; DLBCL, NOS made up the highest percentage (60.6%) Rare histopathological type such as Tcell-rich large B-cell lymphoma/histocyte, Burkitt's lymphoma, plasma-cell lymphoma accounted for 1.4%; 0.3% and 0.7%, respectively Our study results were similar to the finding of Nguyen Khac Tuyen (2021) research which showed that diffuse large B-cell lymphoma comprised the highest proportion (66.67%), followed by marginal zone lymphoma accounting for 12.3% The percentage of diffuse large B-cell lymphoma in our study was much higher than that of Nguyen Phi Hung (2006) while the percentage of follicular lymphoma was lower 4.3.1 Diffuse large B-cell lymphoma In the study; DLBCL, NOS type accounted for 60.6% of B-cell lymphoma cases and 89.9% of diffuse large B-cell lymphoma DLBCL in CNS type accounted for 5.8%; Primary mediastinum(thymic) large B-cell lymphoma accounted for 1.0% Other histopathological types in diffuse large B-cell lymphoma made up a minority Based on the Hans diagram, we classified diffuse large B-cell lymphoma into germinal center (GBC) and the activated/nongerminal (ABC) subtype, and the GBC subtype accounted for 24.9% while ABC subtype accounted for 75.1% This result was consistent with Barrans (2002) and Hans (2004) where the prevalence of subtypes ABC were 55% and 58% 20 In 77 cases with adequate staining of markers BCL2, BCL6, c-MYC, the percentage diffuse large B-cell lymphomas co-expressed the markers BCL2/BCL6 and c-MYC was 22.1% and 5.2% of all cases revealed all markers simultaneously In diffuse large B-cell lymphoma, the expression of CD5 markers was considered a poor prognostic factor, most of CD5 positive cases are of the non-germinal subtype In our study, there were 11 cases DLBCL, NOS (6.2%) expressed CD5 In our study, the mean value of Ki67 in DLBCL, NOS type was 73.8±12.6; that values in DLBCL of CNS and primary mediastinal (thymic) large B-cell lymphoma were 75±12 and 73.3±20.9 respectively There was no difference in Ki67 expression in the types of diffuse large B-cell lymphoma, nor was there any difference in Ki67 index between the germinal and non-germinal subtypes 4.3.2 Marginal cell lymphoma In our study, MZL accounted for 12.3% and was the second common B-cell lymphomas Among MZL, MALT accounted for the highest percentage (7.5% B-cell lymphoma), followed by B-cell lymphoma (accounted 4.1% B-cell lymphoma), splenic marginal lymphoma (accounted for 0.7% cell lymphoma) B) MZL was highly expressed with B-cell markers such as CD20, CD79a, however, a small percentage of cases were negative for CD20 marker (5.6%); The positive rate for BCL2 marker was high (80.1%) but CD10 and BCL6 were rarely expressed Therefore, using markers CD10 and BCL6 helps to distinguish MZL and FL This result was similar to the rate in Olszewski (2013) study which reported that among MZL, MALT accounted for the highest percentage, followed by Nodal MZL and SMZL (5%, 2.4% and 0.7%) 4.3.3 Follicular lymphoma In the study, follicular lymphoma ranked 3rd (6.2%) and the histology grade mainly was grade I, II (44% and 24% respectively); grade IIIA accounted for 20%, grade IIIB accounted for the lowest rate (12%) 21 BCL6 expressed in 16/25 cases in FL (accounted for 64%), CD10 expressed in 21/25 cases (made up 84%); no cases were negative simultaneously with both markers BCL2 was positive in 84% of cases The positive rate of CD10 and BCL2 markers in the low-grade FL was higher than that in the high-grade FL, but this difference was not statistically significant (p>0.05) The Ki67 index in follicular lymphoma ranged from 10% to 70%; the mean was 33.4±18.4 whereas in the low-grade FL had a lower Ki67 expression rate (mean 25.0±13.5) than the high-grade FL (mean 52.25±14.6) (p