Lymphomas Notes


Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Lymphomas essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Lymphomas:

Hodgkin lymphoma

Non-Hodgkin lymphoma

NOTES NOTES LYMPHOMAS GENERALLY, WHAT ARE THEY? PATHOLOGY & CAUSES ▪ Lymphocytic tumors ▪ Nodal lymphomas: develop in lymph nodes ▪ Extranodal lymphomas: develop in/spread to other organs/tissues ▪ Neoplastic B cells do not produce antibodies ▪ Attract non-neoplastic inflammatory cells (e.g. T cells) via chemokines ▪ Activate fibroblasts to make collagen, eosinophils ▪ Metastasis to bone marrow → crowds out normal marrow progenitor cells → decreases healthy erythrocytes/leukocytes/ platelets SIGNS & SYMPTOMS ▪ B (systemic) symptoms: fever, night sweats, weight loss, fatigue, loss of appetite, chills DIAGNOSIS TYPES DIAGNOSTIC IMAGING Hodgkin’s lymphomas ▪ Spread contiguously (to nearby lymph nodes; rarely extranodal) ▫ Prognosis better for Hodgkin’s: contiguous spread allows direct, targeted treatment ▪ Reed–Sternberg cells CT scan, positron emission tomography (PET) scan ▪ Stage of lymphoma Non-Hodgkin’s lymphomas ▪ Spread non-contiguously LAB RESULTS Lymph node biopsy ▪ Confirmation, type TREATMENT ▪ No Reed–Sternberg cells CAUSES ▪ Genetic mutation in lymphocytes → no apoptosis → cell divides → becomes neoplastic cell ▪ Possible link between viruses (e.g. HIV, EBV), lymphomas COMPLICATIONS ▪ Metastasis to spinal cord → spinal cord compression → sensory/motor deficits ▪ Depends on extent, stage, category; age, health of individual; coexisting diseases MEDICATIONS ▪ Chemotherapy SURGERY ▪ Stem cell transplant OTHER INTERVENTIONS ▪ Radiation therapy 402 OSMOSIS.ORG
Chapter 49 Lymphomas HODGKIN'S LYMPHOMA PATHOLOGY & CAUSES ▪ B-cell tumors; Reed–Sternberg cells: large mononuclear, neoplastic cells; two cells fused, two nuclei (resemble owl eyes) TYPES Classical Hodgkin’s lymphoma (CHL) ▪ More common ▪ Reed–Sternberg cells express CD45/CD20; not CD15/CD30 ▪ Histological subtypes: background inflammatory cells, fibrosis Histological CHL subtypes ▪ Nodular sclerosis Hodgkin’s lymphoma ▫ Most common; esp. in young adults ▫ Neoplastic, inflammatory cells surrounded by collagen from fibroblasts forming nodules ▫ Lacunar cells (Reed–Sternberg cells with shrunken cytoplasm, nucleus appears as if in middle of lacuna/lake) ▫ Good prognosis ▪ Mixed cellularity ▫ Second most common; more common in older adults ▫ Prevalent in HIV-positive individuals ▫ Mixed inflammatory background OSMOSIS.ORG 403
composed of eosinophils, neutrophils, plasma cells, histiocytes surrounding Reed–Sternberg cells ▪ Lymphocyte-rich ▫ Reed-Sternberg cells surrounded by lymphocytes ▫ Best prognosis, caught early ▪ Lymphocyte-depleted ▫ Rarest; median age: 30–37 years ▫ No reactive lymphocytes, abundance of Reed–Sternberg cells ▫ Prevalent in HIV-positive individuals ▫ Worst prognosis, advanced stage diagnosis Nodular lymphocyte predominant Hodgkin’s lymphoma ▪ More common in individuals who are biologically male ▪ Abnormal B cells express CD20/CD45; not CD15/CD30 ▪ Lymphocyte-predominant cells; no Reed– Sternberg cells ▫ Large groups of lymphocytes form nodules around lobulate-nucleated “popcorn” cells (variant of Reed– Sternberg cells) ▪ Slow-growing, highly curable ▪ Small risk of transformation to aggressive non-Hodgkin’s lymphoma SIGNS & SYMPTOMS ▪ Painless cervical lymphadenopathy ▫ Mediastinal lymphadenopathy: nodular sclerosis subtype ▪ Cytokine release: fever, drenching night sweats, weight loss ▫ Rarely present with nodular lymphocyte predominant Hodgkin’s lymphoma ▪ B symptoms ▫ Nodular sclerosis: about 50% ▫ Mixed cellularity: common ▫ Lymphocyte-rich: rare ▫ Lymphocyte-depleted: common DIAGNOSIS DIAGNOSTIC IMAGING ▪ CT scan, PET scan LAB RESULTS ▪ Lymph node biopsy STAGING ▪ Stage 1: limited to one lymph node group/ group of adjacent lymph nodes ▪ Stage 2: ≥ two lymph node regions on same side as diaphragm ▪ Stage 3: lymph nodes on both sides (superior, inferior) of diaphragm ▪ Stage 4: lymph nodes superior, inferior to diaphragm; liver/spleen/lungs/bone marrow ▪ Subdivisions ▫ Category A: no symptoms ▫ Category B: B symptoms present ▫ Category E: organs/tissues beyond lymph system 404 OSMOSIS.ORG Figure 49.1 A CT scan of the chest in the coronal plane demonstrating a large mediastinal mass. The mass is a focus of Hodgkin’s lymphoma.
Chapter 49 Lymphomas TREATMENT MEDICATIONS Rituximab ▪ For nodular lymphocyte predominant Hodgkin’s lymphoma ▪ Monoclonal antibody, binds CD20, induces complement-mediated lysis → apoptosis Figure 49.2 The histological appearance of Hodgkin’s lymphoma. Reed–Sternberg cells are pathognomonic of this disease. Figure 49.3 The gross pathology of a spleen that has been infiltrated by Hodgkin’s lymphoma. NON-HODGKIN'S LYMPHOMA PATHOLOGY & CAUSES ▪ B/T cell tumors, no Reed–Sternberg cells TYPES B cell lymphomas ▪ More common ▪ Neoplastic B cells: CD20 on surface ▪ Rate of growth: slow/aggressive/highly aggressive B cell lymphoma subtypes ▪ Diffuse large B cell lymphoma ▫ Aggressive ▫ Most common ▪ Follicular lymphoma ▫ Slow growing ▫ Chromosomal translocation: t(14,18) → BCL2 gene placed after Ig heavy chain promoter → overexpression of BCL2 → inhibition of apoptosis → cell proliferation ▫ BCL2 promotes cell viability, blocks apoptosis ▪ Burkitt lymphoma ▫ Highly aggressive ▫ “Starry sky” appearance under microscope ▫ Stars: tingible bodies (macrophages) with phagocytosed dead neoplastic cells ▫ Sky: dark neoplastic lymphocytes ▫ Chromosomal translocation: t(8,14) → Myc gene moved adjacent to IgH OSMOSIS.ORG 405
promoter sequence → upregulation of Myc gene → Myc gene stimulates cell growth, metabolism → increased cell division ▫ Variant in individuals of African descent: extranodal involvement of jaw, associated with EBV infection ▫ Variant in individuals of non-African descent: extranodal involvement of abdomen (e.g. at ileocecal junction), less frequently associated with EBV infection ▪ Mantle cell lymphoma ▫ Aggressive ▫ Chromosomal translocation: t (11,14) → BCL1 gene moved to Ig promoter → upregulation of BCL1 gene → stimulation of cell growth 406 OSMOSIS.ORG ▪ Marginal zone lymphoma ▫ Indolent ▫ Most common type ▫ Associated with mucosa-associated lymphoid tissue (extranodal) in cases of chronic inflammation of stomach lining (e.g. chronic H. pylori infection) ▫ May occur in lymph nodes (nodal marginal zone lymphoma)/spleen (splenic marginal zone lymphoma) ▪ Lymphoplasmacytic lymphoma ▫ Indolent ▫ Bone marrow, lymph nodes, spleen ▫ Waldenstrom macroglobulinemia: neoplastic cells produce M proteins (IgM) in high levels → IgM released into
Chapter 49 Lymphomas blood → increases blood viscosity T cell lymphomas ▪ Adult T cell lymphoma ▫ AKA leukemia: abnormal leukocytes in bloodstream ▫ Possibly cause: human T-lymphotropic virus (HTLV) ▫ HTLV infects T cells → becomes incorporated into T cell DNA → genetic mutation → adult T cell lymphoma ▪ Mycosis fungoides ▫ T cell lymphoma of of skin, resembles fungal infection ▫ Neoplastic cells: CD4+ helper T cells circulate in blood → Sezary syndrome (erythroderma) SIGNS & SYMPTOMS ▪ Painless lymphadenopathy ▪ B symptoms: release of cytokines ▪ Extranodal involvement of GI tract: bowel obstruction ▪ Extranodal involvement of bone marrow: fatigue, easy bruising, recurrent infections ▪ Extranodal involvement of spinal cord: motor/sensory deficits (esp. legs) Figure 49.4 A PET scan in the coronal plane demonstrating gross lymphadenopathy in the axillary, para-aortic and inguinal chains. The underlying cause is a Non-Hodgkin lymphoma. DIAGNOSIS DIAGNOSTIC IMAGING ▪ CT scan, PET scan LAB RESULTS ▪ Lymph node biopsy TREATMENT MEDICATIONS Rituximab ▪ CD20-positive B cell non-Hodgkin lymphomas Figure 49.5 A diffuse large B-cell lymphoma in a cytology specimen. OSMOSIS.ORG 407
Figure 49.6 The histological appearance of mantle cell lymphoma at low power. This lymph node has been infiltrated by the malignant lymphocytes which have a vaguely nodular architecture. 408 OSMOSIS.ORG Figure 49.7 A diffuse large B-cell lymphoma in a cytology specimen.

Osmosis High-Yield Notes

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