Parks 2 Flashcards
What is a very important thing to consider when you find a swollen lymph node?
Where is it draining from?
What is reactive lymphadenitis?
it is a benign condition in response to infection, inflammation or tumor; may be due to Strep or viral infection - acute nonspecific swelling of the lymph nodes due to proliferation of B or T cells in the lymph nodes in response to a bug
A tender linear streak extending from the wrist to the upper arm; the infection spreads from the portal of entry within the superficial lymphatic vessels
acute lymphangitis
If you have a cold sore on your lip (fever blister), which lymph nodes would you expect to be enlarged?
anterior cervical lymph nodes
**think about where that lymph drains
What are 3 benign reactive hyperplasias?
- follicular hyperplasia
- paracortical hyperplasia
- sinus histiocytosis
Explain the structure of the lymph node (3 layers)
cortex with B cells in follicles
paracortex with T cells
medullary sinuses with macrophages
In mono, is there a B cell reaction or a T cell reaction occuring?
B cells are infected by the EBV virus, but it is a T cell response (lymph node will have paracortical hyperplasia)
With cancers, two processes can occur in regional draining lymph nodes. What are they?
- metastasis
2. no metastasis but reactive changes, or sinus histiocytosis
Is sinus histiocytosis indicative of a metastatic carcinoma?
no; it is commonly found in cases of breast cancer and other cancers, but it is a benign reaction
Are all lymphoid neoplasms malignant?
yes
What is the difference b/w a lymphoma and a leukemia?
lymphoma = mass leukemia = bone marrow and peripheral blood
Where can lymphomas occur?
anywhere in the body, even in the CNS (esp in AIDS)
Are most non-Hodgkins lymphomas B or T cell lymphomas?
B cell
After antigen recognition occurs, where does B cell maturation occur (differentiation into a plasma cell ultimately)?
in the germinal centers of lymph nodes
Malignant plasma cells produce what kind of reaction?
monoclonal (all light chains will be the same)
In follicular lymphomas, what is going on genetically? Why is this important?
translocation places BCL2 right next to IGH heavy chain, which causes BCL2 to be overexpressed; BCL2 stabilizes the mitochondrial membrane on malignant lymphocytes and decreases apoptosis of these cells
What does BCL2 over-expression ultimately do to B cell proliferation?
allows malignant B cells to avoid apoptosis
**BCL2 is expressed to decrease apoptosis
What happens genetically with diffuse large B-cell lymphoma (DLBCL)?
dysregulation of BCL6 leads to no germinal center formation, impaired B cell proliferation, and impaired apoptosis
What is Rituximab used for?
it is a chimeric antibody for the CD20 marker on B cells - used against malignant B cells (ex: non-hodgkins lymphomas)
What is the difference between African Burkitt’s lymphoma and sporadic lymphoma?
African: almost all cases associated with EBV
Sporadic: 15-20% associated with EBV; infects retroperitoneum (abdomen)
In Burkitt’s lymphoma, what is happening on a genetic level?
translocation b/w MYC oncogene and Ig heavy chain gene –> causes overexpression of MYC protein to be overexpressed
**promotes proliferation and stops apoptosis
Very aggressive B cell lymphomas associated with this disease
AIDS
This is a T cell lymphoma in which the skin is the primary site
mycosis fungoides
**has epidermotropism - forms characteristic “nests” within the epidermis
How does mycosis fungoides present on the skin?
large red plaques
What cells are characteristic of mycosis fungoides?
sezary cells with cerebreform nuclei
What is it called when sezary cells from mycosis fungoides enter the blood stream?
sezary syndrome
How does Hodgkin’s lymphoma present?
as a mass
What cell is characteristic of Hodgkin’s lymphoma?
Reed-Sternberg cell
**binucleated cell with mirror-image nuclei
How many subclasses of Hogdkins disease are there? What are the two most common?
5;
- nodular sclerosis (70%)
- mix-cellularity (20%)
What is happening genetically in Hodgkin’s lymphomas?
NF-kB turns ON genes which promote lymphocyte proliferation and survival
What do the Reed Sternberg cells in HL do?
secrete lots of cytokines, some of which (IL-10 and TGF-B) suppress the TH1 response leading to cutaneous anergy
What is a characteristic feature of nodular sclerosis hodgkin’s lymphoma?
mediastinal mass
tumor cells subdivided into nodules
What are 3 symptoms that may make you think about Hodgkin’s lymphomas?
- night sweats/fever
- cough/shortness of breath
- weight loss
What type of cells are seen in the lymphocyte predominant type of HL?
popcorn reed-sternberg cells
What is one important characteristic that we should know about Hodgkin’s lymphomas?
they are very predictive, because they progress in an orderly, contiguous manner
(ex: if they initially present in the chest, they will next affect the next lymph node in line)
**spleen before liver
Contiguous flow through lymph nodes
Hodgkin’s lymphomas
What is the difference between A and B symptoms in Hodgkin’s lymphomas?
If a pt has one or more of the following symptoms: fever, night sweats, weight loss over 10% in 6 months), they are B. If these symptoms are absent, they are A.
Why is TB common in Hodgkin’s lymphomas?
cytokines inhibit TH1 diversion, and cause clinical anergy (no response to infection)
