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)
25
Q
What is this? What is its clinical presentation, immunophenotype, genetics, and clinical course?
A
- 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
Q
Describe and diagnose.
A
- 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
Q
This is a Bcl-2 immunostain in a germinal center. What do you think is going on?
A
- 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
Q
How do pathologists grade follicular lymphoma (FL)?
A
- Based on the number of large cells (centroblasts) present -> this does predict the prognosis
29
Q
What is diffuse large B-cell lymphoma? Describe its clinical presentation, immunophenotype, genetics, and key predictors.
A
- 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)
31
Q
What is the morphology here characteristic of?
A
- 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
Q
What is this morphology characteristic of?
A
- 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”)
34
Q
What do you think this is? Describe the morphology.
A
-
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)
37
Q
What are the clinical presentation and morphology of NLPHL?
A
- 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
44
Q
What malignancy is this? Describe its origin, clinical presentation, and morphology.
A
- 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
47
Q
What is the morphology associated with peripheral T-cell lymphoma NOS?
A
- 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
