Pathoma - WBC Disorders - Lymphoma Flashcards
What is the differential of painless LAD
Chronic inflammation, metastatic carcinoma, lymphoma
What diseases cause follicular hyperplasia (B-cell region) of the lymph node?
Rheumatoid arthritis and HIV
What diseases cause paracortex hyperplasia (T-cell region) of the lymph node?
Viral infections
What diseases cause hyperplasia of the sinus histiocyte in the lymph nodes?
Cancer
What is the basic difference between Hodgkin and Non-Hodgkin lymphoma?
Non-Hodgkins - whole mass is composed of malignant cells Hodgkins - rare neoplastic cells (Reed Sternberg) secrete cytokines that draw in inflammatory cells, leading to a mass
What are the small-, intermediate-, and large-cell Non-Hodgkin’s lymphomas
Small - follicular, mantle cell, marginal zone, small lymphocytic (CLL that involves lymph nodes
Intermediate - Burkitt
Large - diffuse large B-cell
What is the positive marker in follicular lymphoma
CD20+ (small B cells)
What is the mutation in follicular lymphoma
t(14;18) BCL2 translocated to the Ig heavy chain
What is the effect of BCL2 translocation in follicular lymphoma
BCL2 is responsible for stabilizing mitochondrial membranes, preventing cytochrome C from leaking from mitochondria into cytoplasm and thus preventing apoptosis
BCL2 translocation leads to upregulation in the lymph follicle (there is usually no BCL2 expression in lymph nodes) so that there is no apoptosis of dysfunctional B-cells
What is the treatment for follicular lymphoma
Rituximab (anti-CD20 antibody)
What can follicular lymphoma progress to?
Diffuse large B-cell lymphoma
How do you distinguish follicular lymphoma from follicular hyperplasia (infection)
- Disruption of normal lymph node architecture
- Lack of tingible body macrophages
- BCL2 expression in follicles
- Monoclonality
What are tingible body macrophages
Macrophages within the germinal centers that clean up in response to apoptosis
Present in follicular hyperplasia but not in follicular lymphoma (BCL2 prevents apoptosis)
What is the mutation in mantle cell lymphoma
t(11;14)
Cyclin D1 translocated to Ig heavy chain, leading to overexpression of D1 which promotes G1 -> S transition
In what situation does marginal zone lymphoma usually arise?
Chronic inflammatory states (e.g. Hashimoto thyroiditis, Sjogren, H. Pylori gastritis)
This makes sense since the marginal zone arises in resonse to chronic inflammation
Describe the histology of Burkitt lymphoma
“starry sky”
Macrophages within tumor cells = star within sky
Describe the histology of Hodgkin Lymphoma
Reed Sternberg cells
Large B cells with multilobed nuclei and prominent nucleoli (‘owl-eyed nuclei’)
What is the most common subtype of Hodgkin lymphoma and describe it’s characteristics and presentation
Nodular sclerosis
Presents as an enlarging cervical or mediastinal lymph node in a young adult, usually female
Lymph node divided by bands of sclerosis
RS cells present in lake-like spaces (lacunar cells)
