5 Microscopic picture of reactive lymphoid follicles
6 lymphomaDefinition : malignant neoplasm of lymphoid origin, typically causing solid tissue mass usually in form of lymphadenopathy but may be presented as extra nodal mass as in brain or intestine.
7 Epidemiology of lymphomas 5th most frequently diagnosed cancer in both sexesmales > females
8 Causes of lymphomaGenetic alterations causing mutations in chromosomes.Infection specially with viruses as Human T- cell leukemia Lymphoma virus , Epestein Bar virus.Immunosuppression
9 Pathogenesis of lymphoma There is monoclonal expansions of lymphocytic cells at certain developmental stages either of the :immature type which arise from lymphoblast .the mature type which arise from lymphocyte.
10 WHO classification of lymphoid neoplasms B cell neoplasm.T cell neoplasm.Hodgkin lymphoma.
15 Risk factors for NHL immunosuppression or immunodeficiency family history of lymphomainfectious agentsionizing radiation
16 Sites for non Hodgkin lymphoma A- Nodal lymphoma start in the lymph nodes.B-extra nodal lymphoma:- intestine- Central nervous system- Skin- Brain- testis- spleen- ovary
17 Clinical manifestations Variableseverity: range from asymptomatic to extremely ill.Systemic manifestationsweight loss, anorexia.Local manifestationslymphadenopathy, splenomegaly most commonany tissue potentially can be infiltrated
18 Diagnosis of lymphoma A- gross examination B- microscopic examination: requires an adequate biopsy before treatment is initiated So we do :- Haematoxylin and eosin stained sections.- immunohistochemical stained sections using tumor markers.
20 Microscopic picture of Non Hodgkin lymphoma Lost normal histologic architecture of the lymph nodes.Diffuse infiltration of the lymph node by monoclonal type of malignant lymphocytes.Immunohistochemical staining can help in the diagnosis as:T cell lymphoma are +ve for CD3.B cell Lymphoma are +ve for CD20
21 Microscopic picture of reactive lymphoid follicles
28 Epidemiology less frequent than non-Hodgkin lymphoma overall M>F peak incidence in 3rd decade
29 Associated (etiological?) factors Epestein Bar Virus infection.May associate Human Immunodeficiency Virus infection.possible genetic predisposition.
30 Hodgkin lymphomacell of origin: B-lymphocyte present in germinal centre can change to Reed-Sternberg cells (or RS variants) which is the malignant cells but the other surrounding white blood cells in the affected lymph node are reactive cells( polyclonal) not neoplastic cells.
33 A possible model of pathogenesis loss of apoptosistransformingevent(s)EBV?cytokinesgerminalcentreB cellRS cellinflammatoryresponse
34 Microscopic picture of Hodgkin lymphoma Lost normal histologic architecture of the lymph nodes.The only malignant cells is the classic Reed sternberg cell or one of its variants.But the surrounding cells for the RS cells are reactive and not malignant.Immunohistochemical staining can help in the diagnosis as:R.S cell is +ve for CD15, CD30.
35 HODGKIN LYMPHOMA (Hodgkin's Disease) are further subclassified into : (A)Nodular lymphocyte predominance Hodgkin Iymphoma.(B) Classical Hodgkin Iymphoma which include:Nodular sclerosis .Classical Hodgkin lymphoma, lymphocyte-rich.lymphocyte depleted.Mixed cellularity type.