Lymphadenopathy and EBV Flashcards
What is the transit for B cells?
Bone marrow (maturation)
Blood
Enter lymph node through High Endothelial Venule
Migrate to cortex
Begin in mantle zone as naive B cells
Clonal expansion in germinal center in response to antigen
Migrate to marginal zone and differentiate into plasma cells
Exit via efferent lymphatics
What is the transit for T cells?
Thymus (maturation)
Blood
Enter lymph node through High endothelial venules (HEV)
Migrate to paracortex
Clonal expansion in response to antigen
Exit via efferent lymphatics
What are causes of Reactive Lymphadenopathy (also is reactive more likely in children or adults)
Histologic patterns?
(Reactive lymphadenopathy is more common in children)
Infectious: Infectious mononucleosis/cat scratch/others
Autoimmune
Follicular hyperplasia: B cell expansios
Paracortical hyperplasia: T cell expansions
Sinus histiocytosis
What are examples of non Hodgkin lymphomas (neoplasms of mature B cells)
Burkitt lymphoma
Diffuse large B-cell lymphoma
Extranodal marginal zone lymphoma
Follicular lymphoma
Mantle cell lymphoma
What are examples of Neoplasms of mature T cells or NK cellS?
Peripheral T-cell lymphoma unspecified
Anaplastic large-cell lymphoma
Extranodal NK/T cell lymphoma
What are types of Hodgkin lymphomas?
Classical Hodgkin lymphoma
Nodular lymphocyte predominate Hodgkin lymphoma
Important parameters for reactive vs. neoplastic lymphadenopathies in clinical exam
Duration/growth interval?
Size (<1cm is better)?
Location (if location in area that typically does not drain, then bad)? Extent?
Tender (reactive associated) vs. Nontender (neoplastic associated)?
**Fixed **vs. mobile (reactive associated)?
Associated physical exam findings?
Causes for reactive lymphadenopathy?
Infectious
Autoimmune
Drugs
Foreign body
Castleman’s disease
Sarcoidosis
Kikuchi-Fujimoto
Kimura’s disease
Rosai dorfmann
Causes for Neoplastic lymphadenopathy
Lymphoma
Leukemic involvement (lymphoblastic lymphoma/myeloid sarcoma)
Metastatic tumor
What are the reactive lymphandenopathy histologic patterns?
Follicular hyperplasia- Autoimmune/early HIV/Toxoplasmosis
Paracortical hyperplasia- EBV, CMV, Herpes, drugs
Sinus histiocytosis- Draining tumors
Necrotizing- Cat scratch/bacterial/fungal/autoimmune/viral
Granulomatous-fungal, tb
Mixed
JUST KNOW THE BOLDED FIRST THREE
What is rituximab and what is it used for?
Mech of action?
Humanized murine IgG antibody targeting Cd20 antigen. Used to treat Follicular Lymphoma and appears to improve survival
MOA: CDC/ADCC/Apoptosis/ionizing radiation induced cell death
Burkitt Lymphoma
CDs?
Genotype?
How does it present?
CD10+/CD19+/CD20+
c-MYC and immunoglobulin loci: t(8;14) t(2;8) t(8;22)
Adolescent or young adults with rapidly growing extranodal masses (ileocecum); uncommonly presents as leukemia
Aggressive
3 variants:
endemic (EBV associated)
sporatic
Immunosuppression-related (EBV-associated)
Diffuse Large B-Cell Lymphoma
CDs?
How does it present?
CD 19+/CD20+
All ages but commonly adults. Rapidly growing mass/lymphadenopathy
Aggressive
Extranodal marginal zone lymphoma (MALToma)
CDs?
Genotype?
Features?
CD 5-/CD10-/CD19+/CD20+
t(11;18) most common creating MALT1-IAP2 fusion
Localized, associated with chronic infections or inflammatory diseases (H. pylori) or (Hashimoto’s thyroiditis). Indolent. Arises in the lymphoid tissue of mucosal/epithelial-based sites in adults.
Indolent.
