Lymphadenopathies & Lymphomas - Harrington Flashcards
Describe the means by which lymphocytes enter and exit lymphoid organs such as lymph nodes.
Enter the lymph node from the blood via HEVs. Exit via the efferent lymphatics after clonal expansion.
How does the setting of clonal expansion differ between B and T cells?
B cells migrate to the cortex (mantle zone) and expand in the germinal center, then migrate to the marginal zone to differentiate into plasma cells.
T cells migrate to the paracortex and expand there (presumably following costimulation by B cells).
A patient experiences enlargement of “glands” around her cervical spine. They are painful, and biopsy reveals secondary lymphoid follicles. What can you say about the etiology of this condition?
Lymphoid architecture is maintained and the LAD is painful; This is a reactive lymphadenitis, probably relating to an infection.
What criteria on clinical or histological exam can help distinguish a reactive from a neoplastic lymphadenopathy?
Clinical: Duration, size, location, extent, tenderness, mobility.
Histologic: Cellular architecture, dominant cell type, atypias, flow cytometry (immunophenotype)
What are some possible causes of reactive lymphadenopathy?
Describe 4-5 patterns of reactive lymphadenopathy.
Infectious, autoimmune, drugs, foreign body, sarcoidosis, and many other eponymous conditions…
**Follicular/Paracortical hyperplasias, Sinus histiocytosis, **Necrotizing and Granulomatous.
Give the histologic patterns found in lymph nodes under the following conditions:
Viral infection
Rheumatoid arthritis
Tumors in area of drainage
Cat scratch fever (Bartonella henselae)
Toxoplasmosis
Viral: Paracortical hyperplasia
RA: Follicular hyperplasia
Tumors: Sinus histiocytosis
Cat scratch: Necrotizing
Toxoplasmosis: Follicular hyperplasia
(from optional webcast)
What fraction of lymphomas are B-cell?
What fraction of NHLs are nodal?
About 80% of lymphomas are B-cell related.
2/3 of NHLs are nodal.
(from optional webcast)
Describe the Ann Arbor clinical staging system for lymphoma.
What other staging system exists
Stage I (involves 1 LN), II (2 LNs on same side of diaphragm), III (involvement on both sides of diaphgragm), IV (extralymphatic infiltration). A/B suffix (B = presence of B symptoms)
International Prognostic Index (IPI)
(from optional webcast)
A precise etiology for NHLs is not known. However, there are several conditions or pathophysiologies that are thought to contribute. Name 3.
- Chronic inflammation (increases the chance of developing a mutant clone)
- Translocations (usually involving IgH locus)
- Accidents in normal clonal rearrangement
Differentiate between low-grade and high-grade lymphomas with respect to their cell size, localization, and survival.
Low grade: Indolent, small cells, disseminated, kills slowly but surely (incurable; short-term survival is good but long-term is bad)
High grade: Aggressive, large cells, localized, kills quickly but plateaus (curable; long-term survival exceeds low-grades)
What are the most common lymphomas?
DLBCL (Diffuse Large B-Cell Lymphoma)
Follicular Lymphoma
Describe the structure of rituximab.
What is its mechanism of action?
Rituximab is a chimerized IgG (murine Fab, human Fb).
Targets CD20 antigen to eliminate B cells via CDC, ADCC, activation of apoptosis, and delivery of ionizing payload (?)
Follicular Lymphoma
How common is it?
Who is the “sterotypical patient”?
How does it present cilnically?
Follicular Lymphoma
Fairly common; 20% of all lymphomas.
An older (60yo) male.
Generalized, painless adenopathy.
Follicular Lymphoma
What is the most common cytogenetic aberration?
How is its outlook?
Follicular Lymphoma
t(14;18)
Generally indolent; 40% transform to aggressive lymphomas (DLBCL, Burkitt). Advanced stages previously incurable (Anti-CD20 being the first therapy to reduce mortality).
What are reed-sternberg cells?
What markers do they have?
What disease do they indicate?
Multinucleate, B cell derivatives
CD15 and CD30
Hodgkin’s Lymphoma
What are some differences between Hodgkin’s and Non-Hodgkin’s lymphoma?
Hodgkin’s Lymphoma
- Central, Axial Nodes
- Spread contiguously
- Bone Marrow Involvement Rare
Non-Hodgkin’s Lymphoma
- Peripheral Lymph nodes
- Spread non-contiguously
- Bone Marrow Involvement Frequent
What are the 4 classical types of Hosdgkin’s Lymphoma?
What is the non-classical type?
Nodular Sclerosis
Mixed Cellularity
Lymphocyte Predominant
Lymphocyte depleted
Nodular Lymphocye Predominant
Nodular Sclerosis Hodgkin’s Lymphoma
What age is more affected?
Which Gender is more affected?
Site?
Cell Markers?
Morphology?
15-35 years old
M=F
Mediastinal Nodes
CD15, CD30
Lacunar Cells, Dense sclerosis
Mixed Cellularity Hodgkin’s Lymphoma
What age is more affected?
Which Gender is more affected?
Site?
Cell Markers?
Morphology?
Bimodal Ages (young and Old)
M>F
Cervical, Axillary
CD15, CD30
Inflammatory milieu
Nodular Lymphocyte Predominant
What age is more affected?
Which Gender is more affected?
Site?
Cell Markers?
Morphology?
30-50 years old
M>F
Cervical, Axillary
CD20, CD45 (Remember this is the abnormal HL)
Popcorn Cells
Ebstein Barr Virus
What family of viruses does it belong to?
What is it’s genome?
Is it enveloped?
Herpes Virus (specifically gammaherpes)
Double-stranded DNA
Yes