Markers Flashcards
Name the normal B cell immunophenotype.
CD45, CD79a, CD20, IgG kappa or IgG lambda
Name the normal T cell immunophenotype.
CD45, TCR (CD3), CD7, CD4 or CD8
What does a “foward scatter” tell you about cells?
cell size
What does a “side scatter” tell you about cells?
internal granules or segmented nuclei
What is CD34?
hematopoietic stem cell marker (blasts)
What is CD33?
granulocyte marker
What are the 3 major categories of hematological malignancies?
Acute leukemias
Myeloproliferative diseases
Myelodysplasias
What cells are rapidly proliferating in acute leukemias?
blasts
What cells are rapidly proliferating in myeloproliferative diseases?
a similar clone proliferates and differentiates leading to an increase in some type of peripheral blood cell
What cells are rapidly proliferating in myelodysplasias?
a similar clone proliferates and differentiates yielding abnormal blood cell production (low count of some blood cells and abnormal appearance of those cell types)
What cells are just CD34+?
blasts
What cells are CD34+, CD33+?
myeloid blasts
What cells are Tdt+, CD10+?
lymphoid blasts
What cells are CD19+, CD20+?
mature lymphocytes/lymphoma
What are the 3 clonal proliferations which we can call acute leukemias even if blast cell count is under 20%?
t(8,21) RUNX1-RUNX1T1
inv(16) CBFB-MYH11
t(15,17) PML-RARA
What mutation is found in acute promyelocytic leukemia?
t(15;17) PML-RARA
What morphology is unique to APL?
big blasts, cleaved “bat wing” nuclei, many cytoplasmic granules, and Auer rods
What is the immunophenotype of APL?
Weak/absent CD34, HLA-DR, CD13+, CD33+
AML with t(8,21) leads to what affect?
dominant negative repression of myeloid maturation
What morphology is unique to AML with t(8,21)?
some maturation of myelocytes, occasional Auer Rods
What is the immunophenotype of AML with t(8,21)?
CD34+, HLA-DR+, CD13+, weak CD33
How does AML with inv(16) or t(16,16) relate to AML with t(8,21)?
both involve “core binding factor”
What morphology is unique to AML with inv(16)?
mixed granulocyte-monocyte features and increased eosinophils in the blood
What is the immunophenotype of AML with inv(16)?
CD34+, CD117+ (blasts), CD13+, CD33+ (granulocytes), CD14+, CD11b+ (monocytes)
What is the immunophenotype of AML with normal cytogenetics and complex phenotype?
CD34+, CD117+ (blasts), CD 33+ (typically)
t(9;22) is associated with what? Goor or bad prognosis?
BCR-ABL1 in ALL (bad prognosis)
What is the immunophenotpe of ALL with t(9;22)?
CD10+, CD19+, TdT+
t(v;11q23) is associated with what? Good or bad prognosis?
MLL rearranged in ALL (bad prognosis)
What is the immunophenotype of ALL with t(v;11q23)?
CD10-, CD19+, TdT+
t(12;21) is associated with what? Good or bad prognosis?
TEL-AML1 (ETV6-RUNX1) in ALL (good prognosis)
What is the immunophenotype of ALL with T(12;21)?
TdT+, CD34+, CD10+, CD20-
Does hyperdiploid in ALL a good or bad prognosis?
good prognosis
T-ALL is associated with what?
translocation of an oncogene to one of the 3 T-cell receptor promoters
What is the immunophenotype of T-ALL?
TdT+, CD3+, CD5+ (and perhaps myeloid or B-cell antigens as well)
What is the morphology of mastocytosis?
aggregates of bland looking cells, round or spindle shaped, sometimes with eosinophilia
What is the immunophenotype of mastocytosis?
Tryptase, CD117 (C-KIT), CD25
What is the immunophenotype of B cell precursors in the bone marrow (early)?
TdT+, CD10+
What is the immunophenotype of B cell precursors in the bone marrow (late)?
TdT+, CD10+, CD19+, CD20+
What is the immunophenotype of Peripheral (mature) or Memory B cells: ?
CD19+, CD20+
What is the immunophenotype of B cells in germinal centers?
CD10+ (some), CD19+, CD20+
What is the immunophenotype of plasma cells?
CD20-, CD38+, CD138+
Name the 3 Ig promoters and what chromosomes they are located on.
IgH (14q32) Ig lambda (22q11) Ig kappa (2p12)
What types of cells are proliferated in CLL?
CLL is thought to be derived from the most mature forms of B-cells, or inactive “memory B-cells”.
Anatomic distribution of the malignant cells in CLL?
Peripheral blood> Lymph nodes (marginal zone) > Bone Marrow
The appearance of >30% of what cells in a blood smear of CLL is a good prognosis?
smudge cells
What peripheral blood smear finding is a bad sign in CLL?
Increasing fraction of prolymphocytes
What are the two findings in a lymph node of someone with CLL?
1) “Pseudofollicular” (collections of slightly larger cells which are undergoing DNA synthesis and mitosis)
2) Effacement of normal architecture
What is the normal immunophenotype of someone with CLL?
Light Chain Restricted (κ or λ), CD5+, CD23+, CD20 weak
What immunophenotype markers are associated with a bad prognosis in CLL?
ZAP70+ and CD38+ (markers of somatic hypermutation)
What are the most common genetic abnormalities seen in CLL? Which one is good, which one is bad?
80% show abnormalities by FISH
1) del13q14.3 (if this only, good prognosis)
2) trisomy 12
3) del11q22-23
4) del17p13 (p53 region is BAD prognosis))
What are the 2 major differences between CLL and MCL?
1) NO proliferation centers in they lymph nodes of MCL patients
2) MCL patients are CD23-, CD20 STRONG
What genetic abnormality is found in MCL?
t(11;14)(q13;q32) is a fusion protein of IgH and the oncogene Cyclin D1
What is the consequence of the t(11;14)(q13;q32) in MCL?
This leads to overexpression of cyclin D1 which pushes the cell through the cell cycle (G1 phase to S-phase).
Anatomic distribution of the malignant cells in MCL?
Lymph nodes > bone marrow, spleen, peripheral blood, GI tract
What lymph node findings are unique in MCL?
o Usually homogeneous effacement
o “Starry sky”
o Ki-67 immunostain shows increased mitotic rate
What is the immunophenotype of MCL?
Light Chain Restricted (κ or λ), CD5+, CD23-, CD20 STRONG
What are the two forms of plasma cell neoplasm he discussed?
1) Monoclonal gammopathy of uncertain significance (MGUS)
2) Multiple myeloma (mean survival 3-4 years)
Severe form of plasma cell neoplasms present with what?
multiple lytic bone lesions (plasma cell myeloma); pain, fractures, renal failure
Anatomic distribution of the malignant cells in plasma cell neoplasms?
Bone marrow»peripheral blood
What would you expect to see in a peripheral smear of someone with MGUS (mild plasma cell neoplasm)?
Rouleaux (little stacks of RBCs)
What is the immunophenotype of plasma cell neoplasm?
Light Chain Restricted (κ or λ), CD38+++, CD138+++, CD19-, CD20-
What are the 2 major genetic findings in plasma cell neoplasms?
1) Translocation of IgH to various oncogenes (FISH) in about 2/3 of cases.
2) Trisomies of ODD NUMBERED chromosomes
List the 5 genetic abnormalities in plasma cell neoplasms that are poor prognostic markers.
Serum beta 2 microglobulin t(4;14) FGFR3 t(14;16) C-MAF t(14;20) MAFB del 17p (p53 region)
Grade in follicular lymphoma (FL) is dependent on finding what cells in bone marrow?
More centroblasts (larger, less-dark ones), higher grade!
Anatomic distribution of the malignant cells in FL?
Lymph nodes > Bone marrow (40-70%) > Peripheral blood (maybe)
What does a lymph node look like in someone with FL?
Lymph node (enlarged with many follicles) o No polarity (large-to-small cells) o No tingible body macrophages o Fewer mitotic figures than normal o Germinal center stains for Bcl-2
What is the immunophenotype of someone with FL?
CD19+, CD20+. CD10+ (60%). BCL-2+ (90%). BCL-6+ (85%)
What is the major genetic finding in FL?
t(14;18)(q32;q21)+ in >85% (BCL2 gene)
What is the consequence of t(14;18)(q32;q21)+ in FL?
Failure of germinal center B-cells to apoptose (because they overexpress an anti-apoptotic protein, Bcl-2) because centroblasts translocate Bcl-2 to an IgH promoter.
40% of patients with Diffuse large B-cell lymphoma present with what?
Extranodal disease (GI tract, bone marrow, other)
What is the immunophenotype of Diffuse large B-cell lymphoma?
CD19+, CD20+. CD10+ (30-60%)
What are some genetic findings in Diffuse large B-cell lymphoma?
- t(v, 3q27)(v, BCL-6) in ~30%;
- t(14;18) in 20-30%
- Multiple other translocations/deletions can occur
Describe the typical patient presenting with Hodgkin lymphoma.
- Males, age 30-50
- Localized or diffuse adenopathy
- Often involvement of cervical, mediastinal, or abdominal lymph nodes, and/or spleen
What are the two subtypes of Hodgkin lymphoma (and what are their prognoses)?
Classical Hodgkin Lymphoma (curable with chemo/RT; 97% 10 yr survival rate)
Nodular Lymphocyte Predominant Hodgkin Lymphoma (80% 10 yr survival, 3-5% progress to diffuse large cell B-cell lymphoma)
What cells are specific to Hodgkin lymphoma?
Reed/Sternberg cells: Large lymphoid cells with mono- or bi-nucleate appearance, huge eosinophilic nucleoli; overall horseshoe shape is likely
An HL lymph node that is criss-crossed by fibrous bands is in what morphological subtype?
Nodular sclerosis pattern
An HL lymph node that is NOT criss-crossed by fibrous bands is in what morphological subtype?
Mixed cellularity pattern
An HL lymph node thats background is mostly lymphocytes is in what morphological subtype?
Lymphocyte rich pattern
An HL lymph node thats background is mostly R/S cells is in what morphological subtype?
Lymphocyte depleted pattern
A lymph node in NLPHD has what findings?
- Nodular appearance
- Mummified R/S cells (smaller, less prominent nucleoli)
- “Popcorn-looking” L&H cells
What is the immunophenotype of classical HL?
R/S cells are too fragile for Flow cytometry
CD30+ (>90%), CD15+ (>80%), Pax5+ (>90%) (B-cell transcription factor), CD20-/wk
What is the immunophenotype of NLPHD?
CD30- (>80%), CD15- (>100%), Pax5+ (>95%), CD20+ (>95%), T cells surround R/S cells
Why does HL occur?
Reed Sternberg cells are B-cells which went into germinal centers expecting to die, but instead acquired both anti-apoptotic mutations or anti-apoptotic genes from EBV (NFkB expression) and disguised themselves by disabling IgH expression.
How does the molecular pathology behind HL and NLPHD differ?
Generally the same as classical, but NO disabling of IgH expression
What is the immunophenotypic findings of NK cells?
CD3+ cytoplasmic
What is the immunophenotypic findings of gamma-delta T-cells?
CD3+ surface
What is the immunophenotype of developing T cells?
TdT+ and CD7+
What is the immunophenotype of mature T cells?
CD3+ (surface), CD7+ and CD4+ or CD8+
True or false: almost every T cell lymphoma looks the same.
FALSE: T cell lymphomas do not have any apparent trends (presentation is highly variable!!!)
What is the one test you can perform if you expect a T cell lymphoma?
Clonality can be demonstrated by PCR-based studies of the TCR gene.
What T cell malignancy is immunophenotypically like a helper T cell and has many skin lesions?
Mycosis fungoides
If Mycosis fungoides begins to involve the blood, what do you call it?
Sezary syndrome
What are the major presenting features of Angioimmunoblastic T-Cell Lymphoma?
- Rapidly progressive critical illness
- Diffuse lymphadenopathy
- Hepatosplenomegaly
- Skin rash
- Cold autoimmune hemolytic anemia
- Evidence of immunocompromise
Angioimmunoblastic T-Cell Lymphoma is a proliferation of what type of cells? (immunophenotype)
T-follicular helper cells (CD3+, CD4+, CD10+)
What two strange immunophenotypic findings are characteristic of Angioimmunoblastic T-Cell Lymphoma and must be stained for?
1) they express a marker usually seen on germinal center B-cells, CD10+.
2) Residual follicular dendritic cell (FDC) frameworks still present and stain for CD21+
What drugs should NOT be used to treat Angioimmunoblastic T-Cell Lymphoma?
Standard chemotherapeutic agents have a high morbidity rate in AILT because their immunocompromising side effects are compounded by the immunocompromise inherent to the disease itself.
What is the typical clinical presentation of someone with Peripheral T Cell Lymphoma NOS?
- Diffuse lymphadenopathy
- B symptoms (fever, night sweats, weight loss)
- Paraneoplastic features
- Eosinophilia
- Pruritis
- Hemolytic anemia
True or false: Peripheral T Cell Lymphoma NOS is an aggressive disease.
true! 5 year survival only 20-30%
What are the expected lymph node features in Peripheral T Cell Lymphoma NOS?
- Expanded Paracortex
* Normal architecture is effaced
Describe the immunophenotype of Peripheral T Cell Lymphoma NOS. (even variants and unexpected findings)
What’s expected: CD3, 5, 7, and 4 or 8
What’s usually seen: Loss of one or more of the above
Variants: “Double positives” (CD4+, CD8+)
Unexpected markers: CD20 (B-cell), CD56 (macrophage/monocyte), CD30 (R/S cell)
