Non-Hodgkins Lymphoma Pathology Flashcards
Normal lymph node
What is the “dark zone” of the lymph node?
area that is reacting to Ag → centroblasts are undergoing proliferation, somatic mutation & isotype switching
Centrocytes
small cleaved lymphocytes exhibiting surface Ab in the light zone
(centroblasts are in the dark zone)
mantle zone of lymph node contains _____
naive b-cells
Marginal zone (just outside mantle zone) contains ______ (2)
- naive B-cell
- memory B-cells
(they’re just chillin’)
Ki67 role in dx
proliferation marker for lymph follicle
(proliferation may be normal, but it can aid in dx)
Non-Hodgkin’s Lymphoma (malignant lymphoma) arises within the _____.
lymph nodes, not in bone marrow (can metastasize there though)
(or other organs rich in lymphoid tissue; leukemias arise in bone marrow and metastasize to lymph nodes. “leukemia/lymphoma” used when we aren’t sure where it started first)
Neoplastic cells are monoclonal, how can we tell if the cells (T cell or B cells) are monoclonal?
- B cells: light chain restriction
- T cells: TCR arrangement
CD5+ is a good dx marker for which 2 N-H lymphomas?
- SLL/CLL
- Mantle
(Rules out follicular and marginal zone)
Hodgkin’s Lymphoma (malignant lymphoma) risk factors (3)
- Immunodeficiency
- Chronic autoimmune diz
- Chronic infections
(immune system being overly stimulated)
2 Clinical findings of Non-Hodgkin’s Lymphoma (malignant lymphoma)
- painless lymphadenopathy
- B-type sx: fatigue, fever, wt. loss, night sweats
(may have extranodal sx if metastasized: abdominal pain, rash, sensorimotor, chest pain)
Low-grade lymphoma is well differentiated tumor; High-grade is a poorly differentiated tumor. Which has the better prognosis?
Low-grade
(low grade: painless lymphadenopathy, no B-symptoms; high-grade is the opposite)
Hodgkin’s lymphoma staging is the similar as leukemia. What is the general staging?
1: 1 lymph node involved or single extranodal site
1B: + systemic sx (B-sx)
2: 2+ lymph nodes on same side of diaphragm
3: both sides of diaphragm
4: extranodal involvement, both sides of diaphragm
How do you tell the difference between benign and malignant lymph node changes?
- malignant: painful
- benign: gets better, goes down
(bx to confirm)
What is the main finding that indicates a benign reactive changes (hyperplastic) of lymph nodes?
interfollicular area (spaces btwn follicles)
(mantle zone, dark/light zones present)
What is the most important immunophenotypic finding of benign changes to the lymph node?
bcl-2 negative (anti-apoptotic protein) in the follicle
(CD3+, CD20+ cells present)
Why is this a neoplastic follicle (2)?
- loss of zonal definition w/absent mantle zone (loss of polarity)
- No tingible body MF
MC form of adult indolent NHL?
follicular lymphoma
Mutation in follicular lymphoma (type of NHL)
t(14;18) → BCL-IgH fusion gene
(anti-apoptotic effect)
Key terms of histopathology that indicate follicular lymphoma?
- atypical lymphocyte
- cleaved v. non-cleaved
(more importantly, look for cytogenetics and immunophenotype)
MC type of NHL?
diffuse large B-cell lymphoma (also MC adult NHL)
Diffuse Large B-Cell lymphoma may arise from which two hematologic cancers?
- Follicular lymphoma
- CLL→Richter transformation
dx?
(left: intermediate power; right: high power)
Diffuse B-cell Lymphoma (high grade tumor)
(any lymph node may be affected)
What does this tell you?
CD10 is a malignant marker
(found in Burkitt lymphoma, follicular & diffuse large b-cell. Next you need to determine cytogenetics)