6.6 Lymphoma Flashcards
What is a lymphoma?
Neoplastic proliferation of lymphoid cells that forms a mass
Can be in or out of a node
What are the 2 major division of lymphoma?
Non-Hodgkin (more common) and Hodgkin
What are the divisions of Non-Hodgkin lymphoma?
Based on cell size:
Small B cells: follicular, mantle cell, marginal zone, small lymphocytic lymphoma
Intermediate B cells: Burkitt lymphoma
Large B cells: diffuse large B cell lmphoma
What is Follicular Lymphoma?
neoplastic proliferation of small B cells (CD20+) that form follicle-like nodules
When does follicular lymphoma present and how?
Late adulthood, with painless LAD
Patient in late adulthood presents with painless LAD and is found to have t(14;18), what is a likely Dx?
Follicular Lymphoma
What drives the development of follicular lymphoma?
t(14;18) that moves BCL2 to locus of heavy chain Ig on chromosome 14
BCL2 stabilizes Cyt C in the mitochondria preventing apoptosis
Follicular lymphoma treatment
Reserved for symptomatic patients
Low dose chemo or rtuximab (anti-CD20 Ab)
Potential complication of follicular lymphoma
Progression to diffuse large B cell lymphoma presenting as an enlarging lymph node
Rituximab
Anti-CD20 Ab
What is the function of BCL2? Relation to follicular lymphoma?
Stabilizes mitochondrial membrane and prevents apoptosis
B cells in the follicles of nodes should undergo apoptosis regularly and should have low expression of BCL2
Follicular Lymphoma has increased production of BCL2 preventing apoptosis in the nodes
How is follicular lymphoma differentiated from reactive follicular hyperplasia?
1) Disruption of normal node architecture
2) Lack of tingible body macrophages (sign of no apoptosis when not present)
3) BCL2 expression in follicle
4) Monoclonality
How can monoclonality of B cells be gauged?
Look at the kappa:lambda light chain ratio
Normal: 3:1
Abnormal and sign of monoclonality: 20:1 or greater
Patient in late adulthood presents with painless LAD and found to have B cell expansion in region immediately adjacent to the follicle. Dx?
Mantle Cell Lymphoma
Mantle Cell Lymphoma
Neoplastic Small B cells (CD20+) expands the mantle zone
Presents in late adulthood with painless LAD
What drives Mantle Cell Lymphoma?
t(11;14)
Cyclin D1 on 11 to Ig heavy chain on 14
Cyclin D1 promotes G1/S transition in the cell cycle, facilitating neoplastic proliferation
What disease is assoc. c t(11;14) and what is the molecule overexpressed?
Mantle Cell Lymphoma
Cyclin D1
Marginal cell lymphoma
Small B cells expanding the margin of the lymph node
Margins tend to only exist during chronic inflammatory states, so this is assoc. c them: Hashimoto thyroiditis, Sjogren, H pylori
MALToma a subtype involving mucosal sites
Patient with gastritis from H pylori found to have a gastric MALToma, what is the expected outcome for this?
With resolution of H pylori infection it is expected to regress
Young patient found to have an extranodal growing mass on the mandible. Histology shows a starry sky appearance. What is the genetic mutation driving this?
Burkitt Lymphoma of the jaw
t(8;14) most commonly overexpressing c-myc promoting cell growth
What are the two forms of Burkitt Lymphoma?
African: jaw most commonly
Sporadic: abdomen
What age group gets Burkitt Lymphoma?
Kids and young adults
Diffuse large B cell lymphoma
Proliferation of large B cells that grow diffusely in sheets
Most common form of NHL
Aggressive because non-differentiated cells
Arises sporadically or from transformation of low-grade lymphoma (follicular)
Presents in late adulthood as an enlarging lymph node or an extranodal mass
