lymphoma Flashcards
describe LAD by region and cause
- folliculary hyperplasia is B cell proliferation (early HIV, rheumatoid arthritis)
- paracortex hyperplasia is T cell proliferation (viral infections)
- sinus histiocyte hyperplasia: lymph node that is draining a tissue with cancer.
nonhodgkin vs. hodgkin: malignant cells, compostion of mass, clinical features, spread,extranodal involvement, staging, leukemic phase, association with viruses
nonhodgkin: cells are B cells of different sizes; mass is made of lymphoid cells, features: painless LAD, usually in older adults, though 20-40 in some subtypes; spreads with multiple, peripheral, noncontiguous spread and common extranodal involvement. staging not important. leukemic phase occurs. associated with HIV, immunosuppression.
hodgkin: Reed sternberg (owl eye) cells. mass is mostly made of reactive tissue (inflammatory cells and fibrosis). contiguous spread. local, single group of nodes. extranodal involvement rare. B symptoms common (fever, weight loss, night sweats). staging guides therapy (mostly radiation). no leukemic phase. associated with EBV
follicular lymphoma
neoplastic proliferation of small B cells that form follicle-like structures. patient has painless LAD. disrupts the follicular architecture. driven by a 14;18 translocation. Bcl-2 on chromosome 18 translocates to a position on chromosome 14 near the Ig heavy chain locus, causing overexpression of Bcl2. this allows the cell to escape apoptosis (we don’t want this in the follicles- these cells are undergoing somatic hypermutation!)
tx is for those who are symptomatic- try chemo or rituximab (anti-CD20).
complication: progression to diffuse large b-cell lymphoma- you would see an enlarging lymph node.
how do you tell the difference between follicular lymphoma and reactive follicular hyperplasia?
- disruption of normal follicular architecture
- lack of tingible body macrophages in the geminal centers (macrophages are there to eat up apoptotic cells in normal germinal centers. in follicular lymphoma, there isn’t apoptosis, so no apoptosis, and no macrophages)
- Bcl2 expression in follicles (they aren’t supposed to express Bcl2),
- monoclonality (follicular hyperplasia is polyclonal)
mantle cell lymphoma
neoplastic prolif of small B cells that expands the mantle zone. presents in late adulthood with painless LAD.
driven by t(11,14). cyclin D1 on chromosome 11 translocates to Ig heavy chain on chromosme 14. overexpresion of cyclin D1 promotes G1/S transition in the cell cycle.
marginal zone lymphoma
neoplastic prolif of b cells that expands the marginal zone (which is outside of the mantle). mantle zone only expanded in cases where the b cells have been activated and is formed by post-germinal center B cells. inactive lymph nodes don’t really have a marginal zone. therefore, marginal zone lymphoma is related to conditions of chronic inflammation- Hashimoto thyroiditis, sjogren syndrom, and H. pylori gastritis.
note that MALTomas are marginal zone lymphomas at mucosal sites, and that gastric MALTomas may regress with treatment of H. plyori.
burkitt lymphoma
neoplastic prolif of intermediate sized b cells. associated with EBV. classically presents as an extranodal mass in a kid or young adult. african form involves the jaw; sporatic form involves the abdomen. driven by an 8;14 translocation- this puts c-myc near the Ig heavy chain locus on chromosome 14.
high mitotic index and stary sky appearnace on biopsy.
diffuse large B cell lymphoma
neoplastic prolif of large B cells that grow diffusely in sheets. most common form of NHL. clinically aggressive. arises sporadically or from transformation of low grade lymphoma (ie. follicular). late adulthood as an enlarging lymph node or an extranodal mass.
hodgkin lyphoma subclassifications
reactive inflammatory cells make up the bulk of the tumor. they form the basis for classification of HL. subtypes: nodular sclerosis, lymphocyte-rich, mixed cellularity, lymphocyte depleted.
nodular sclerosis hodgkin lymphoma
enlarging cervical or mediastinal lymph node, esp. in a female. lymph node is divided by bands of sclerosis with RS cells in lake like spaces (lacunar cells).
most common
what should I know about lymphocyte-rich, mixed cellularity, and lymphocyte depleted types of hodgkin lymphoma
lymphocyte rich has the best prognosis, lymphocyte depleted is the most aggressive and usually seen in elderly and HIV+ people. mixed cellularity often has abundant eosinophils because reed sternberg cells make IL-5.
