ICL 11.1: Lymphoma I Flashcards
(48 cards)
what is lymphoma?
malignancy of lymphocytes that typically begins in the lymph nodes
where do lymphomas originate?
~2/3 Actually arise in lymph nodes
~1/3 of cases arise in extra nodal sites
like the GI tract, CNS, skin, eyes
what are the two major categories of lymphomas?
- Non-Hodgkin lymphoma
B cell (most common), T cell, and NK cell lymphomas
- Hodgkin Lymphoma
5 subtypes, WHO classification
classic and non-classic
what’s the difference between lymphoma and leukemia?
both are malignancies of the hematopoietic and lymphoid tissues…
but lymphomas are a malignancy of lymphoid cells that typically begins in the lymph nodes
and leukemias are a malignancy in either lymphoid or myeloid cells that begin in bone marrow
are lymphomas mono or polyclonal?
all lymphomas are derived from a single transformed cell and thus are monoclonal
B and T cell tumors are composed of cells derived from specific stages of their normal differentiation pathways
which lymphomas are derived from germinal center B cells?
follicular lymphoma
burkitt lymphoma
diffuse large B cell lymphoma
hodgkin lymphoma
which lymphomas are derived from precursor B cells?
B lymphoblastic leukemia/lymphoma
which lymphomas are derived from pre-GC B cells?
mantle cell lymphoma
which lymphomas are derived from post-GC B cells?
marginal zone lymphoma (MALT)
lymphoplasmacytic lymphoma
CLL/SLL
DLBCL
plasmacytoma
which lymphomas are derived from precursor T cells?
T lymphoblastic lymphoma/leukemia
where are B cells normally located in the lymph node?
cortex
where are T cells normally located in the lymph node?
paracortex
where are plasma cells normally located in the lymph node?
medulla
what happens to B cells once they’ve matured in the BM?
Naïve B-cell lymphocyte, move from bone marrow to lymph node cortex
they congregate in germinal follicle until they’re expose to antigens
naïve B cells in the germinal center proliferate, undergo somatic hypermutation, and differentiate into plasma cells
what are the different parts of the lymph node?
slide 11
explain the progression of the B cell through the lymph node dark and light zone
- naive B cell enters dark zone
- undergoes clonal expansion
- undergoes somatic hypermutation
- B cell enters light zone
the cells that underwent disadvantageous mutations get turned into apoptotic cells in the light zone and are destroyed
the B cells that had advantageous mutations get turned into plasma cells or memory B cells
what’s the clinical presentation of lymphoma?
Fever, night sweats, weight loss (any malignant disease)
Painless lymphadenopathy
Splenomegaly, hepatomegaly or mass
what’s the Ann Arbor staging system for lymphomas?
Stage 1: localized disease, single lymph node region or single organ
Stage 2: two or more lymph node regions on the same side of the diaphragm
Stage 3: two or more lymph node regions above and below the diaphragm
Stage IV: widespread disease, multiple organs, with or without lymph node involvement
what’s the Lugano classification system of lymphomas?
bulk ln Hodgkin lymphoma is defined as a mass greater than one-third of the thoracic diameter on CT of the chest or a mass >10 cm
for NHL, the recommended definitions of bulk vary by lymphoma histology
stages 1-4
how can you diagnose a lymphoma?
Fine-needle aspirate is inadequate for initial diagnosis. Excisional biopsy is recommended. Core-needle biopsy may suffice when excision not feasible
flow cytometry would help you with immunophenotyping
FISH would help you see translocations
PET and CT scans
***morphology is required to establish diagnosis
what is the philadelphia translocation?
t(9;22) seen in CML
contains afusion genecalledBCR-ABL1
this causes a tyrosine kinasesignalingprotein that is “always on”, causing the cell todivideuncontrollably by interrupting the stability of the genome and impairing various signaling pathways governing the cell cycle
presence of this translocation is a highlysensitivetest for CML, since all cases of CML are positive forBCR-ABL1
However, the presence of the Philadelphia chromosome is not sufficientlyspecificto diagnose CML, since it is also found inacute lymphoblastic leukemia and occasionally inacute myelogenous leukemia as well as mixed-phenotype acute leukemia (MPAL).
what is the Deauville 5-point scoring system?
an internationally accepted and utilized five-point scoring system for the Fluorodeoxyglucose (FDG) avidity of a Hodgkin’s lymphoma or Non-Hodgkin’s lymphoma tumor mass as seen on FDG
1: no 18-FGD uptake
2: uptake < mediastinal blood pool
3: uptake > mediastinum and < liver
4: uptake moderately > liver at any site
5: uptake markedly > liver at any site and/or new sites of disease
X: new areas of uptake unlikely to be related to lymphoma
what are the main characteristics of NHL?
B-cell or T-cell
Mostly malignant cells
Widespread disease at Dx
Waldeyers ring common site
Noncontiguous spread
Low grade types incurable
what are the main characteristics of HL?
Unique Reed-Sternberg cell (CD15 and CD30 +)
Many reactive cells, few malignant cells
Localized disease
Waldeyers ring rarely involved
Predictable contiguous spread
Generally curable
