Hematologic Malignancies III - Strom 03.23.15 Flashcards
1
Q
What do you see here? What are the key cells and zones?
A
- Normal/reactive lymph nodes: training base for pathogen-specific B-cells
- If B-cells react with host, or fail to react w/pathogen, they are induced to die (99% apoptosis rate), and are picked up by macros containing remnants of their nuclei -> remnants tend to pick up hematoxyin, and are called tingible bodies
- Germinal centers: centrocytes (small), centroblasts (large), follicular dendritic cells
- Also paracortex and mantle zone
2
Q
How does degree of differentiation “tend” to affect the severity of malignancies?
A
- In general, malignancies that appear to be derived from more differentiated cells are less aggressive (i.e., chronic vs. acute leukemias), but there are many exceptions
- However, malignancies that appear to be derived from differentiated cells can transform into more aggressive forms
3
Q
What are some non-morphologic markers of B-cell maturation? What immunophenotypic markers do we need to know?
A
- Non-morphologic markers of maturation include surface Ig type and molecular features of the Ig loci (evidence of class switching and of somatic hypermutation)
- Some more commonly used immunophenotypic markers of key stages of B-cell development:
1. Precursor B-cells: TdT, CD10
2. Throughout life cycle: CD19, CD20
3. Follicular area: CD10
4. Long-lived plasma cells: CD38, CD138, CD20-
4
Q
In addition to flow cytometric measurements, how else can you assess immunophenotype? Provide some examples.
A
- By visualizing binding of the relevant monoclonal Abs directly to paraffin embedded tissues
- Examples:
1. CD20 in germinal centers and mantle zones
2. CD10 in some B-cells in germinal centers
3. CD5 or CD3 in T-cells (mostly in paracortex)
5
Q
What is a key pathogenetic point in B-cell development? Provide some examples.
A
- Translocation of an oncogene to an Ig promoter
- Promoters include: IgH (14q32), Ig lambda (22q11), and Ig kappa (2p12)
6
Q
What is staging?
A
- A way of gauging the extent of clinical involvement
- There are different staging schemes for different lymphomas
7
Q
Where might you see expression of follicular lymphoma, and what is the associated oncogene?
A
- Primarily lymph nodes
- Also bone marrow and peripheral blood
- Bcl2 + Ig promoter = overexpressed oncogene
8
Q
Where might you see expression of Burkitt lymphoma?
A
- Primarily the GI tract
- Also lymph nodes and bone marrow
- Myc + Ig promoter = overexpressed oncogene
9
Q
Where might you see expression of chronic lymphocytic leukemia (small lymphocytic lymphoma)?
A
- Primarily peripheral blood
- Also bone marrow and lymph nodes
10
Q
What “stage” of B-cell is CLL thought to be derived from?
A
- Thought to be derived from the most mature forms of B-cells -> most of those are inactive “memory B-cells”
- Some are found in the “marginal zone”, a poorly defined region just outside the mantle zone
11
Q
What do you see here? What are the clinical presentation, involved sites, and morphology?
A
- Chronic lymphocytic leukemia: dx usually fairly obvious when peripheral smear reviewed; can be confirmed by immunophenotyping (flow cytometry)
- Clinical presentation: lymphocytosis in older males, high familial incidence
- Involved sites: Peripheral blood > bone marrow, lymph nodes
- Morphology: small lymphocytes with little cytoplasm and mature (dense chromatin) and “smudge” cells in peripheral blood (normal counterpart: memory B-cell)
12
Q
What do you see here? What is this characteristic of?
A
- CLL/SLL has a characteristic “pseudofollicular” appearance in lymph nodes
- Pseudofollicles appear to be collections of slightly larger cells undergoing DNA synthesis and mitosis
13
Q
What are the genetic and immunophenotype correlates of CLL/SLL? How do these impact prognosis?
A
- Genetics: 80% show abnormalities by FISH -> del13q14.3 > trisomy 12 > del11q22-23, del17p13 (p53 region)
- Immunophenotype: light chain restricted (kappa or lambda), CD20 (weak), CD5+, CD23+
-
Key clinical predictors:
1. Immunophenotype: ZAP-70 or CD38 = bad (markers of somatic hypermutation status)
2. Genetics: 17p (p53) deletion = bad; 13q deletion only = good - Clinical course: chronic, except when it’s not
14
Q
What do you see here? What are the clinical presentation, involved sites, and morphology?
A
- Mantle cell lymphoma
- Clinical Presentation: lymphadenopathy and/or lymphocytosis in older males; can look clinically like CLL at presentation
- Involved sites: Lymph nodes > bone marrow, spleen, peripheral blood, GI tract
-
Morphology:
1. Peripheral blood: small lymphocytes, little cytoplasm; “smudge”cells; normal counterpart a mantle cell
2. Lymph node: homogeneous effacement, starry sky -
NOTE: CLL common, and at dx you must distinguish it from a more aggressive lymphoproliferative disease with some similar properties: mantle cell lymphoma.
1. One key difference: no proliferation centers in the lymph nodes in MCL
15
Q
What are the genetic and immunophenotype correlates for MCL? How do these affect prognosis?
A
-
Genetics: t(11;14)(q13;q32) (IgH;Cyclin D1) ALWAYS seen by FISH -> overexpression of cyclin D1 (CCND1) pushes cell through cell cycle (G1 to S phase)
1. Translocation of oncogene to IgH promoter (worked out pathogenesis -> recurring theme) - Immunophenotype: similar to CLL -> light chain restricted (kappa or lambda), CD5+, but CD20 strong, CD23-
- Clinical course: more agressive than CLL
- Key clinical predictors: Ki-67 immunostain (mitotic rate; shown here)
16
Q
What is this a characteristic image of?
A
- Burkitt lymphocytes: very blue (basophilic) cytoplasm, unusual cyto vacuoles, and more variation in nuclear size, shape than in low-grade lymphomas (CLL/SLL)
- Cells growing fast (one with the beaded-up nucleus at far right is a mitotic figure), and die fast too - dead cells taken up by macros scattered around in tumor (large cells w/clear cytoplasm, which at low power make tumor look like a starry sky); dark fragments of dead nuclei in some of the macros
17
Q
What do you see here? What are the clinical presentation, involved sites, and morphology of its sporadic expression?
A
- Clinical Presentation: abdominal mass in children or young adults, higher incidence in HIV+ people
- Involved sites: ileo-cecal area/ovaries/kidneys
- Morphology: normal counterpart memory B cells
- Cytology: intermediate size cells w/basophilic, vacuolated cytoplasm
- Tissue: usually homogeneous effacement, high growth rate, starry sky
18
Q
What is this? What are the clinical presentation, morphology, and pathogenesis of the endemic presentation?
A
- Endemic Burkitt lymphoma
- Clinical Presentation: jaw/facial bone mass in child (age 4-7) in p. falciparum malaria-endemic area, i.e., Ghana, Papua New Guinea (most common cancer in kids in these areas)
- Morphology: Same as sporadic Burkitt’s (normal counterpart memory B-cells)
- Genetics: same as sporadic, but EBV positive genes (can contribute oncogene, but this alone doesn’t explain mechanism)
- Pathogenesis: relationship b/t malaria and EBV poorly explored
19
Q
What are the immunophenotype and genetics associated with Burkitt?
A
- Immunophenotype: typical B-cell markers (CD10, 19, and 20)
- Genetics: translocation of oncogene (MYC, on 8q24) to an Ig promoter -> Either IgH (14q32), kappa light chain (2p12), or lambda light chain (22q11), in other words, translocation (8;14) or (8;2) or (8;22)
20
Q
What is this? What are the associated clinical presentation, forms, involved sites, and lab findings?
A
- Clinical Presentation: older individuals
- Mild forms: asymptomatic lab findings (monoclonal gammopathy of uncertain significance, MGUS)
- Severe forms: multiple lytic bone lesions (plasma cell myeloma); pain, fractures, renal failure
- Involved sites: bone marrow >> peripheral blood
- Lab findings: mild forms -> increased total protein, Rouleaux (little “stacks” of RBCs) noted on peripheral smear
21
Q
What lab test do you order if you see increased serum protein?
A
- Electrophoresing the (non-reduced, non-denatured) serum proteins (serum protein electrophoresis, SPEP)
- Most labs “reflexively” identify any abnormal single protein species via immunofixation electrophoresis
- In IFE, 6 identical lanes of serum proteins are run and transferred to solid support matrix, then visualized w/a reagent that stains most proteins (ELP) or reagents that stain particular types of immunoglobulin proteins
1. Normals: all Ig lanes show up as smears, collections of polyclonal Igs
2. When a clone secreting a single Ig is present, a single band (in this image shown on the right, monoclonal IgG kappa antibodies) is seen
22
Q
What do you think is going on in this bone marrow biopsy?
A
- Plasma cells w/a lot of cytoplasm, and nucleus off to one side of the cell (eccentric) -> in most cases, the clumpy nuclear chromatin is evident to the pathologist
- Large, obvious golgi apparati in cytoplasm – usually evident as perinuclear clear space that early hematopathologists called a “hof”
- Large collections of cells in bone marrow tend to erode bone, and leave radiologically evident bone lesions (hence the term multiple myeloma)
23
Q
What are the immunophenotype, genetics, clinical course, and key negative predictors associated with this bone marrow biopsy? Hint: note the eroded bone.
A
- Immunophenotype: CD38+, 138+, 19-, 20-; light chain restricted
- Genetics: translocation of IgH to various oncogenes (FISH) in about 2/3 of cases; trisomies (hyperdiploidy) of odd numbered chromosomes are common
- Clinical course: MGUS (1%/yr progress to MM); multiple myeloma median survival 3-4 years
- Key negative clinical predictors: serum beta 2 microglobulin, t(4;14) FGFR3, t(14;16) C-MAF, t(14;20) MAFB, del 17p (p53 region
- NOTE: presence of clonal plasma cells can be confirmed by flow cytometry, and immunostaining, but that’s not usually necessary -> clinicians use evolving set of criteria to distinguish between the clinically active forms (multiple myeloma) and forms which have not (yet) had much clinical impact (MGUS)
24
Q
What is the critical pathogenetic mechanism of follicular lymphoma?
A
- Failure of germinal center B-cells to apoptose b/c they overexpress anti-apoptotic protein, BCL-2 (that is translocated to an IgH promoter region)
25
What is this? What is its clinical presentation, immunophenotype, genetics, and clinical course?
- Enlarged lymph node with many follicles (follicular lymphoma)
- _Clinical presentation_: lymphadenopathy in older ppl, but can be otherwise asymptomatic; bone marrow involved in 40-70% of cases, but can also involve peripheral blood
- _Immunophenotype_: CD19, 20, 10+ (60%), BCL-2+ (90%), BCL-6+ (85%)
- _Genetics_: t(14;18)(q32;q21)+ in \>85%, but multiple other translocations/deletions can occur; Bcl-2 gene located at chrom 18q21 translocated to IgH promoter region
- _Clinical course_: quite variable; depends on stage, grade, and genetics; 30% progress eventually to diffuse large B-cell lymphoma
26
Describe and diagnose.
- No polarity (large-to-small cells)
- No tingible body macrophages (no apoptotice B-cells being digested by macros)
- Fewer mitotic figures than normal -\> one of the few types of cancer in which the number of mitotic figures is LOW relative to its normal counterpart
- FOLLICULAR LYMPHOMA
27
This is a Bcl-2 immunostain in a germinal center. What do you think is going on?
- Follicular lymphoma
- Normal/reactive germinal center B-cells are ready to apoptose, and do not express anti-apoptotic protein Bcl-2
- Follicular lymphoma B-cells do express it – that’s why they survive in the germinal center
28
How do pathologists grade follicular lymphoma (FL)?
- Based on the number of large cells (centroblasts) present -\> this does predict the prognosis
29
What is diffuse large B-cell lymphoma? Describe its clinical presentation, immunophenotype, genetics, and key predictors.
- Garbage-can category of somewhat loosely defined B-cell lymphomas (25-30% of B-cell lymphomas) -\> lg category defined primarily by morphology (can be divided into germinal center & post-germinal center)
- _Clinical presentation_: rapidly growing adenopathy, elderly individuals, 40% present with extranodal disease (GI tract, bone marrow, other)
- _Immunophenotype_: CD19+, CD20+, CD10+ (30-60%) Subtype definition?
- _Genetics_: t(v, 3q27)(v, BCL-6) in ~30%, t(14;18) in 20-30%, but multiple o/translocations/deletions can occur
- _Clinical course_: depends on stage
- _Key clinical predictors_: bone marrow involvement, bone marrow appearance (concordant vs. discordant)
30
What is the clinical presentation of Hodgkin lymphoma?
- Males 30-50
- Localized, or diffuse adenopathy
- Often with involvement of cervical, mediastinal, or abdominal lymph nodes, and/or spleen
31
What is the morphology here characteristic of?
- **Classical Hodgkin**
- _Reed-Sternberg cells_: large lymphoid cells with mono- or binucleate appearance, and huge eosinophilic nuclei; overall horseshoe shape likely
- Diverse background cells: small lymphos, plasma cells, eosinophils, neutrophils, histiocytes
- Often _collagenous bands_ that give the lymph node a nodular appearance at a lower power
32
What is this morphology characteristic of?
- **Nodular lymphocyte predominant Hodkin lymphoma**
- _Reed-Sternberg cells_ (called lympho-hisotcytic, L&H cells) smaller, and have less prominent nucleoli -\> sometimes show large, densely staining nuclei with little cytoplasm ("mummified forms," or "popcorn cells")
33
How did Reed-Sternberg cells become cancerous?
- Found some other way to survive the germinal center, and stopped expressing surface Igs
- Like follicular lymphoma cells, R-S cells are B-cells that entered germinal centers expecting to die, but acquired anti-apoptotic mutations, like constitutive NFKB expression (or anti-apoptotic genes from EBV), and disguised themselves by disabling IgH expression
- There is reason to think they acquired some genetic instability early in the process
- Likely genetic instability
34
What do you think this is? Describe the morphology.
- **Morphology**:
1. Normal lymph node architecture wholly or partially effaced
2. Can be criss-crossed by fibrous bands (_nodular sclerosis pattern_) or not (_mixed cellularity pattern_)
4. Can show background that’s mostly lymphos (_lymphocyte-rich pattern_)
5. Can show a large number of R/S cells (_lympho-depleted pattern_)
35
What are the immunophenotype, genetics, clinical course, and key clinical predictors associated with Classical Hodgkin lymphoma?
- _Immunophenotype_: CD30+, 15+, PAX5+ (B-cell transcription factor), CD20 weak (flow cytometry not currently useful b/c RS cells too fragile)
- _Genetics_: not currently useful (requires micro-dissection)
- _Clinical course_: 1) curable with chemo/radiation therapy, 2) 97% 10-yr survival
- _Key clinical predictors_: 1) stage, 2) histologic type
36
How do NLPHL cells become cancerous?
- Similar features to classical HD, but these RS (LH) cells do express surface Igs
37
What are the clinical presentation and morphology of NLPHL?
- _Clinical presentation_: similar to HL (30-50 males with localized or diffuse adenopathy and often involvement of cervical, mediastinal, abdominal lymph nodes, and/or spleen)
- _Morphology_: nodular, with mostly lymphos in the background, but with popcorn cells (lympho-histocytic, L&H) in place of classic RS cells -\> morphology alone is NOT SUFFICIENT to make the diagnosis
38
Your patient with back pain has elevated serum protein - what do you do?
SPEP (serum protein electrophoresis)
39
What are the immunophenotype and clinical course associated with NLPLH?
- _Immunophenotype_: CD30-, 15-, PAX5+ (B-cell transcription factor), CD20+, T-cells surround the RS cells -\> distinct to this subtype (flow cytometry not currently useful b/c RS cells too fragile and few)
- _Clinical course_: 80% 10-yr survival, tx at Stage I may not be needed, 3-5% progression to diffuse large B-cell lymphoma
40
What is the correlation between differentiation state and clinical behavior for T-cell lymphoma/leukemias?
- No good correlation (in contrast to B-cells, where less differentiation typically means more aggressive)
41
What are the most commonly used immunophenotypic markers that help us place malignancies in T-cell camp?
- TdT - CLT
- CD3+ (cytoplasmic- CLT, surface- PLT)
- CD4+ and 8+ (central lymphoid tissue, CLT)
- CD4+ or CD8+ (peripheral lymphoid tissue, PLT)
- CD7+ - CLT, PLT
42
What immunophenotyping helps us identify NK and gamma-delta T-cell malignancies?
- _NK_: CD3+, cytoplasmic
- _Gamma-delta_: CD3+, surface
- CD4-, CD8+/-, CD7-
- Spleen, mucosa, peripheral blood, skin
43
What useful genetic tools do we have for T-cell malignancies?
- No simple recurrent themes:
1. Most do NOT involve translocation of oncogene to T-cell receptor promoter (no simple analogy to B-cell lymphomas)
2. Many show complex karyotypes
3. Only a few have been genetically identified
- One useful genetic tool: **TCR clonality** (PCR); does not apply to NK cells
44
What malignancy is this? Describe its origin, clinical presentation, and morphology.
- _Mycosis fungoides_: normal counterpart CD4+ T-cell
- _Clinical presentation_: patchy, flat, red skin lesions that can progress to thick, psoriasis-like, ulcerated lesions; can involve bloodstream (Sezary), usually in older patients
- _Morphology_: 1) Cytology - normal size lymphos with indented nuclei, 2) Tissue - bland looking lymphos that invade epidermis, 3) Bloodstream - bland lymphos with cerebriform nuclei
- Image is an early patch lesion, commonly called: Pautrier micro-abscesses, even though they are not abscesses
45
What are the immunophenotype and genetics of mycosis fungoides?
- _Immunophenotype_: CD3, 5, 4+
1. Tends not to express the complete package of 4 or 5 normal T-cell Ags, so ID'ing T-cells that lack one or more of them is a way to help dx
- _Genetics_: clonal rearrangement of TCR gene
- Can be hard to distinguish this kind of lesion from some kind of chronic inflammatory/reactive condition. In the latter, though, T-cells present will (on molecular analysis) usually contain variety of re-arranged TCR genes. In MF, as in other T-cell malignancies, one clone is predominant – so just one rearranged form of the TCR will be present
46
What are the clinical presentation, normal counterpart, and involved cells in peripheral T-cell lymphoma NOS (not otherwise specified)?
- Currently make up about 30% of T-cell lymphomas
- _Clinical presentation_: diffuse LAD, B symptoms (fever, night sweats, weight loss), paraneoplastic features (eosinophilia, pruritis, hemolytic anemia)
- _Normal counterpart_: unclear
- _Involved sites_: just about anywhere, but usually NOT blood stream
47
What is the morphology associated with peripheral T-cell lymphoma NOS?
- Lymph node: _expanded paracortex_, effacement of normal architecture (variations: distinct subsets of atypical cells)
- Some T-cell malignancies also show proliferation of cells w/lg amt of eosinophilic cytoplasm, cohesive kind of clustering, and normal looking nuclei -\> “_epitheiiod histiocytes_” are clue to presence of T-cell malignancy, particularly if more prominent near capsule of node
- Dx often depends on pathologist’s basic microscopic skills. If normal architecture effaced, AND a collection of cells showing similar histologic characteristics are present, AND those cells don’t show cohesive, gland-forming architecture typical of a carcinoma, we look into whether this could be a T-cell lymphoma. In the cases shown, most pathologists can pick out pop of cells that is "just too uniform" for normal paracortex
48
What are the immunophenotype, genetics, and clinical course associated with peripipheral T-cell lymphoma NOS?
- _Immunophenotype_: CD3, 5, 7, and 4 or 8 (usually see loss of 1 or more of these) -\> usually seals dx
- _Variants_: double positives (CD4/8+) and unexpected markers - CD20 (B-cell marker), CD56 (macro/mono marker), CD30 (RS cell marker)
- _Genetics_: complex karyotype - multiple chrom gains and losses, mult chrom deletions, no pattern has emerged
- _Clinical course_: aggressive 5-yr survival 20-30%
