Hematologic Malignancies III Flashcards
What is the recurring theme in B cell malignancies?
translocation of an oncogene to an Ig promoter, results in overexpression of the oncogene
ex: Myc moves to IgH promoter (14q32) region
As a general rule (with exceptions), more aggressive B-cell malignancies arise from ____ and less aggressive malignancies arise from ____.
less mature/differentiated cells (i.e., precursor B cells in bone marrow); more mature and well differentiated cells (i.e., plasma cells and memory B cells)
True or false: malignancies that appear to develop from well differentiated B cells can transform into more aggressive forms.
True
Name a non-morphologic indicator of B cell maturation.
Ig expression: surface IgM on interfollicular, naive B cells; surface IgG on activated perifollicular B cells
Name the immunophenotypic markers of the following key stages of B cell development:
- Precursor B cells (in bone marrow)
- Interfollicular B cells
- Follicular B cells (germinal center centroblasts/centrocytes)
- Perifollicular/fully activated B cells (plasma & memory B cells)
- TdT, CD10, CD19, CD20
- CD19, CD20
- CD10, CD19, CD20
- CD38, CD138
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of chronic lymphocytic leukemia/lymphoma (CLL)?
Clinical: lymphocytosis in older males; high familial incidence
Anatomic: peripheral blood > bone marrow, lymph nodes; in lymph nodes memory B cells in mantle zone (perifollicular area) Micro: smudge cells in peripheral blood - small LCs with little cytoplasm and mature (dense) chromatin; pseudofollicular lymph nodes - collections of slightly larger cells undergoing DNA synthesis/mitosis
What is the immunophenotype and genetic/molecular pathogenesis of chronic lymphocytic leukemia/lymphoma (CLL)?
Immunophenotype: light chain restricted (K or L), CD5+, CD20 weak, Cd23+
Genetics: 80% show FISH abnormalities; del 13q14.3 (good) > trisomy 12 > del 11q22-23, del 17p13 (P53 region-BAD)
What is the clinical course and prognosis of chronic lymphocytic leukemia/lymphoma (CLL)?
chronic (except when it’s not); prognosis: ZAP-70 and CD38 expression is bad; 17p deletion is bad; 13q deletion only is good; >30% smudge cells good; increasing fraction of prolymphocytes is bad
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of mantle cell lymphoma (MCL)?
Clinical: lymphadenopathy and/or lymphocytosis in older males, can resemble CLL at presentation but MCL is more aggressive
Anatomy: lymph nodes > BM/spleen/peripheral blood/GI tract
Micro: smudge cells and small LCs (little cytoplasm) in peripheral blood; lymph nodes with homogenous effacement “starry sky”
*Key difference btw MCL and CLL: no proliferation centers in lymph node in MCL
What is the immunophenotype and genetic/molecular pathogenesis of mantle cell lymphoma (MCL)?
IP: light chain restricted (K or L); CD5+, CD20 strong, CD23-
Genetics: t(11;14)(q13;q32) (IgH; Cyclin D1) always seen by FISH
What is the clinical course and prognosis of mantle cell lymphoma (MCL)?
more aggressive than CLL; key predictor is the Ki-67 immunostain which shows mitotic rate
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of sporadic Burkitt lymphoma?
Clinical: abdominal mass in children or young adults; higher incidence in HIV+ patients
Anatomy: ileo-cecal area/ovaries/kidneys
Micro: memory B cells: intermediate sized with basophilic/vacuolated cytoplasm; lymph nodes with homogenous effacement, high growth and death rate; “starry sky” appearance because of the large cells with clear cytoplasm (macrophages); variation in nucleus size and shape
What is the immunophenotype and genetic/molecular pathogenesis of sporadic Burkitt lymphoma?
IP: normal B cell markers - CD10+, CD19+, CD20+
Genetics: translocation of MYC (8q24) to an Ig promoter - either IgH (14q32) or a light chain - K (2p12) or L (22q11); that is: translocation (8;14), (8;2), or (8;22)
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of endemic Burkitt lymphoma?
Clinical: jaw/facial bone mass in child age 4-7 in p. falciparum malaria endemic area (i.e., Ghana, Papua New Guinea)
Anatomy: jaw/facial bone
Micro: memory B cells, same as sporadic Burkitt’s
What is the immunophenotype and genetic/molecular pathogenesis of endemic Burkitt lymphoma?
IP: same as sporadic Burkitt’s
Genetics: same as sporadic Burkitt’s but EBV positive
Molecular pathogenesis is poorly understood
What is the clinical course and prognosis of sporadic and endemic Burkitt lymphoma?
with treatment can achieve 8 year survival rate, even 30% of high-risk cases (this is outside information to maintain consistency of malignancy information)
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of plasma cell neoplasms (PCN)?
Clinical: common in elderly; can be mild (asx lab findings–MGUS) or severe (multiple lytic bone lesions–plasma cell myeloma) with pain, fractures, and renal failure; labs show inc. total protein and Rouleaux (stacks of RBCs on smear)
Anatomy: BM»_space; peripheral blood
Micro: plasma cells have lots of cytoplasm, eccentric nucleus, clumpy chromatin, large and obvious Golgi (hof) “blue sky clearing” by nucleus; lots of these cells collecting in BM can leave bone lesions (seen radiologically, hence multiple myeloma)
What is the immunophenotype and genetic/molecular pathogenesis of plasma cell neoplasms (PCN)?
IP: CD38+++, CD138+++, CD19-, CD20-; light chain restricted
Genetics: translocation of IgH to various oncogenes in 2/3 of cases; trisomies of odd numbered chromosomes are common
What is the clinical course and prognosis of plasma cell neoplasms (PCN) [differentiated between MGUS and MM]?
MGUS: 1%/year progress to MM
MM: median survival 3-4yrs
Negative predictors: serum beta2 microglobulin; t(4;14) FGFR3; t(14;16) C-MAF; t(14;20) MAFB; del 17p - p53 region
What is IFE?
immunofixation electrophoresis: run lanes of proteins, transfer to support matrix and visualize with reagent stain (either stain most all proteins or only certain Ig proteins); normally will show lanes of smears (polyclonal proteins) but abnormal will show a single band indicating that monoclonal proteins are present
What is the clinical presentation, anatomic distribution of proliferation, and microscopic appearance of follicular lymphoma?
Clinical: lymphadenopathy (big, non-tender lymph nodes) in older patients, can otherwise be asx
Anatomy: germinal centers in lympho nodes; can involve BM and peripheral blood
Micro: cells of variable size, no tingible body macrophages, fewer mitotic figures than normal
What is the immunophenotype and genetic/molecular pathogenesis of follicular lymphoma?
IP: CD19+, CD20+, CD10+, Bcl-2+, Bcl-6+
Genetics: Bcl-2 (18q21) overexpression (failure of B cells to apoptose), often due to translocation of oncogene to IgH promoter region; t(14;18)(q32;q21); many others