Lymphadenopathy Flashcards
What is lymphadenopathy
Lymphadenopathy refers to enlarged lymph nodes
When is lymphadenopathy usually painful
Usually seen in lymph nodes that are draining a region of acute infection (acute lymphadenitis)
In what condition can painless LAD be seen
Chronic inflammation (chronic lymphadenitis)
Metastatic carcinoma
Lymphoma
In inflammation, lymph node enlargement is due to
In inflammation, lymph node enlargement is due to hyperplasia of particular regions ofthe lymph node
1. Follicular hyperplasia (B-cell region) is seen with rheumatoid arthritis and early stages of HIV infection, for example.
2. Paracortex hyperplasia (T-cell region) is seen with viral infections (e.g., infectious mononucleosis).
3. Hyperplasia of sinus histiocytes is seen in lymph nodes that are draining a tissue with cancer.
Neoplastic proliferation of lymphoid cells that forms a mass
May arise in a lymph node or in extranodal tissue
Divided into non-Hodgkin lymphoma (NHL, 60%) and Hodgkin lymphoma (HL, 40%)
NHL is further classified based on cell type (e.g., B versus T), cell size, pattern of cell growth, expression of surface markers, and cytogenetic translocations
1. Small B cells - follicular lymphoma, mantle cell lymphoma, marginal zone
lymphoma, and small lymphocytic lymphoma (i.e., CLL cells that involve tissue)
2. Intermediate-sized B cells-Burkitt lmphoma
3. Large B cells - diffuse large B-cell lymphoma
What condition could this be
Lymphoma
Non-Hodgkin lymphoma can be further classified based on
NHL is further classified based on
Cell type (e.g., B versus T)
Cell size
Pattern of cell growth
Expression of surface markers
Cytogenetic translocations.
Neoplastic proliferation of small B cells (CD20+) that form follicle-like nodules
Presents in late adulthood with painless lymphadenopathy
Driven by t(14;18)
1. BCL2 on chromosome 18 translocates to the Ig heavy chain locus on chromosome 14.
2. Results in overexpression of Bcl2, which inhibits apoptosis
Treatment is reserved for patients who are symptomatic and involves low-dose chemotherapy or rituximab (anti-CD20 antibody).
Progression to diffuse large B-cell lymphoma is an important complication; presents as an enlarging lymph node
What condition could this be
Follicular lymphoma
How is follicular lymphoma distinguished from reactive follicular hyperplasia
Disruption of normal lymph node architecture (maintained in follicular hyperplasia)
Lack of tingible body macrophages in germinal centers (tingible body macrophages are present in follicular hyperplasia)
Bcl2 expression in follicles (not expressed in follicular hyperplasia)
Monoclonality (follicular hyperplasia is polyclonal)
Presents in late adulthood with painless lymphadenopathy
Driven by t(11;14)
1. Cyclin D1 gene on chromosome 11 translocates to Ig heavy chain locus on chromosome 14.
2. Overexpression ofcyclin D1 promotes G1/S transition in the cell cycle, facilitating neoplastic proliferation
Neoplastic proliferation of small B cells (CD20+) that expands the mantle zone
What condition could this be
Mantle cell lymphoma
Associated with chronic inflammatory states such as Hashimoto thyroiditis, Sjögren syndrome, and H pylori gastritis
Neoplastic proliferation of small B cells (CD20+) that expands the marginal zone
What condition could this be
Marginal zone lymphoma
Neoplastic proliferation of intermediate-sized B cells (CD20+); associated with EBY
Classically presents as an extranodal mass in a child or young adult
1. African form usually involves the jaw
2. Sporadic form usually involves the abdomen
Driven by translocations of c-myc (chromosome 8)
1. t(8;14) is most common, resulting in translocation of c-myc to the Ig heavy chain locus on chromosome 14
2. Overexpression o f c-myc oncogene promotes cell growth.
Characterized by high mitotic index and ‘starry-sky’ appearance on microscopy
What condition could this be
Burkitt lymphoma
What is a diffuse large B-cell lymphoma
Neoplastic proliferation of large B cells (CD20+) that grow diffusely in sheets
1. Most common form of NHL
2. Clinically aggressive (high-grade)
Arises sporadically or from transformation of a low-grade lymphoma (e.g. follicular lymphoma)
1. Presents in late adulthood as an enlarging lymph node or an extranodal mass
What is the effect of cytokine production by RS cells
- Occasionally results in ‘B’ symptoms (fever, chills, weight loss, and night sweats)
- Attract reactive lymphocytes, plasma cells, macrophages, and eosinophils
- May lead to fibrosis
Neoplastic proliferation of Reed-Sternberg (RS) cells, which are large B cells with multilobed nuclei and prominent nucleoli (‘owl-eyed nuclei); classically positive for CD15 and CD30
What condition could this be
Hodgkin lymphoma
What are the subtypes of HL
Reactive inflammatory cells make up a bulk of the tumor and form the basis for classification of HL. Subtypes include
1. Nodular sclerosis
2. Lymphocyte-rich
3. Mixed cellularity
4. Lymphocyte-depleted
