CH6 - 5) Lyphadenopathy, Lymphoma, HL Flashcards
What is lymphadenopathy (LAD)?
it refers to enlarged lymph nodes
Painful LAD is usually seen in what?
lymph nodes that are draining a region of acute infection (acute lymphadenitis)
Painless LAD can be seen with what?
chronic inflammation (chronic lymphadenitis), metastatic carcinoma, or lymphoma.
In inflammation, lymph node enlargement is due to what?
hyperplasia of particular regions of the lymph node
What is follicular hyperplasia seen with?
(B-cell region) rheumatoid arthritis and early stages of HIV infection, for example.
What is paracortex hyperplasia seen with?
(T-cell region) viral infections (e.g., infectious mononucleosis).
What is involved with hyperplasia of sinus histiocytes?
It is seen in lymph nodes that are draining a tissue with cancer.
What is lymphoma?
Neoplastic proliferation of lymphoid cells that forms a mass; may arise in a lymph node or in extranodal tissue
What is lymphoma divided into?
non-Hodgkin lymphoma (NHL 60%) and Hodgkin lymphoma (HL 40%)
NHL further classified based on what?
cell type (e.g., B versus T), cell size, pattern of cell growth, expression of surface markers, and cytogenetic translocations, - small, intermediate and large B cells
What are some examples of small B cells?
follicular lymphoma, mantle cell lymphoma, marginal zone lymphoma, and small lymphocytic lymphoma (i.e.. CLL cells that involve tissue)
What are some examples of intermediate-sized B cells
Burkitt lymphoma
What are some examples of large B cells
diffuse large B-cell lymphoma
What is the overall frequency for NHL?
60%
What is the overall frequency for HL?
40%
What are the malignant cells of NHL?
Lymphoid cells
What are the malignant cells of HL?
Reed-Sternberg cells
What is the composition of mass for NHL?
lymphoid cells
What is the composition of mass of HL?
Predominantly reactive cells (inflammatory cells and fibrosis)
How does NHL present clinically?
Painless lymphadenopathy, usually arises in late adulthood
How does HL present clinically?
Painless lymphadenopathy occasionally with ‘B’ symptoms, usually arises in young adults
What is the spread of NHL?
Diffuse: often extranodal
What is the spread of HL?
Contiguous; rarely extra nodal
Do you use staging in NHL?
Limited importance
Do you use staging in HL?
Guides therapy; radiation is the mainstay of treatment.
Is there a Leukemic phase in lymphoma?
Occurs in NHL but not in HL
What is follicular lymphoma?
Neoplastic proliferation of small B cells (CD20+) that form follicle-like nodules
How does follicular lymphoma present clinically?
in late adulthood with painless lymph adenopathy
What is follicular lymphoma driven by?
t(14;18)
How does t(14:18) result in follicular lymphoma?
BCL2 on chromosome 18 translocates to the Ig heavy chain locus on chromosome 14 this results in overexpression of Bcl2, which inhibits apoptosis
What is the treatment for follicular lymphoma?
is reserved for patients who are symptomatic and involves low-dose chemotherapy or rituximab (anti-CD20 antibody).
What does follicular lymphoma progress to and how does it present?
diffuse large B-cell lymphoma which is an important complication and presents as an enlarging lymph node
How is follicular lymphoma distinguished from reactive follicular hyperplasia?
1) disruption of normal lymph node architecture (maintained in follicular hyperplasia) 2) Lack of tangible body macrophages in germinal centers (tangible body macrophages are present in follicular hyperplasia) 3) Bcl2 expression in follicles (not expressed in follicular hyperplasia) 4) Monoclonality (follicular hyperplasia is polyclonal)
What is mantle cell lymphoma?
Neoplastic proliferation of small B cells (CD20+) that expands the mantle zone
How does mantle cell lymphoma present clinically?
presents in late adulthood with painless lymph adenopathy
What is mantle cell lymphoma driven by?
t(ll;14)
How does t(11;14) result in mantle cell lymphoma?
1) Cydin D1 gene on chromosome 11 translocates to Ig heavy chain locus on chromosome 14. 2) Overexpression of cydin Dl promotes Gl/S transition in the cell cycle, facilitating neoplastic proliferation
What is marginal zone lymphoma?
Neoplastic proliferation of small B cells (CD 20+) that expands the marginal zone
What is marginal zone lymphoma associated with?
chronic inflammatory states such as Hashimoto thyroiditis, Sjogren syndrome, and H pylori gastritis
What is the marginal zone formed by?
post-germinal center B cells.
What is MALToma?
it is marginal zone lymphoma in mucosal sites.
How might Gastric MALToma regress
with treatment of H Pylori,
What is burkitt lymphoma?
Neoplastic proliferation of intermediate-sized B cells (CD20+);
What is butkitt lymphoma associated with?
EBV
How does burkitt lymphoma classically present?
as an extranodal mass in a child or young adult
What is specific about the african form of burkitts lymphoma?
usually involves the jaw
What does the sporadic form of Burkitts lymphoma usually involve?
the abdomen
What is Burkitt lymphoma driven by?
Driven by translocations of c-myc (chromosome 8)
What is the most common translocation for Burkitts lymphoma?
t(8;14) is most common,
In Burkitts lymphoma what does t(8:14) result in?
translocation of c-myc to the Ig heavy chain locus on chromosome 14.
What does overexpression of c-myc oncogene do?
promotes cell growth
How is Burkitts lymphoma characterized?
by high mitotic index and ‘starry-sky’ appearance on microscopy
What is diffuse large B-cell lymphoma?
Neoplastic proliferation of large B cells (CD20+) that grow diffusely in sheets
What is the most common form of non-hodgkins lymphoma?
Diffuse large B-cell lymphoma
Describe diffuse large B-Cell lymphoma clinically?
Clinically aggressive (high-grade)
How does diffuse large B-cell lymphoma arise?
either sporadically or from transformation of a low-grade lymphoma (e.g., follicular lymphoma)
How does diffuse large B-cell lymphoma present?
Presents in late adulthood as an enlarging lymph node or an extranodal mass
What is Hodgkins Lymphoma?
Neoplastic proliferation of Reed-Slernberg (RS) cells,
What are Reed-Slernberg cells?
large B cells with multilobed nuclei and prominent nucleoli (‘owl-eyed nuclei’);
Hodgkins lymphoma is classically positive for what?
CD15 and CD30
What do RS cells secrete?
cytokines.
What are the symptoms for HL
Occasionally results in ‘B’ symptoms (fever, chills, and night sweats)
In HL what do the RS cells attract?
reactive lymphocytes, plasma cells, macrophages, and eosinophils
What may the RS cells in HL lead to?
fibrosis
What makes up a bulk of the tumor and form the basis for classification of HL?
Reactive inflammatory cells
What are the subtypes of reactive inflammatory cells in HL?
Include 1. Nodular sclerosis 2. Lymphocyte-rich 3. Mixed cellularity 4. Lymphocyte-depleted
What is the most common subtype of HL?
Nodular sclerosis (70% of all cases),
What is the classic presentation for nodular sclerosis?
it is an enlarging cervical or mediastinal lymph node in a young adult, usually female
Dsecribe the lymph node in nodular sclerosis?
It is divided by bands of sclerosis; RS cells are present in lake-like spaces (lacunar cells),
What are lacunar cells?
Lake like spaces in the lymph node where the RS cells are present
What type of HL has the best prognosis of all types?
Lymphocyte-rich
In HL mixed cellularity is often associated with what?
abundant eosinophils (RS cells produce IL-5).
What is the most aggressive HL type and in whom is it usually seen?
Lymphocyte-depleted is the most aggressive of all types; usually seen in the elderly and HIV-positive individuals