Haematology Flashcards
What nonreceptor tyrosine kinase is abnormal in chronic myeloid leukaemia. What is the nature of this abnormality
ABL
Abnormality involves a chromosomal translocation 9:22 to the BCR gene. This produces a chimeric, constitutively active tyrosine kinase
What is the genetic abnormality that results in Burkitt lymphoma
Chromosomal translocation of MYC gene 8:14, resulting in increased production of MYC protein
What type of malignancies are associated with JAK2 abnormalities, and by what mechanism? What type of protein is JAK2, and what what type of genetic abnormality is usually associated with it
Myeloid neoplasms. This is because JAK2 becomes constitutively active and no longer needs signalling from haematopoeitic growth factors such as EPO.
JAK2 is a nonreceptor tyrosine kinase (other non tyrosine receptors on the cell membrane receive the growth factor)
Point mutations
What are mature cells of lymphoid origin
NK cells
B cells
T cells
What are mature cells of myeloid origin
Platelets, erythrocytes (red cells), basophils, eosinophils, neutrophils, monocytes
What are the three categories of myeloid neoplasm
Acute myeloid leukaemia: immature progenor cells accumulate in the bone marrow
Myelodysplastic syndromes: ineffective haematologists resulting in peripheral cytopenias
Myeloproliferative syndromes: increased production of one or more terminally differentiated cell lines
How are lymphocytic lymphomas vs leukaemia defined in basic terms
By the usual distributions of the disease:
-leukaemia: starts in bone marrow, spills out into peripheral blood
-lymphoma: form discrete tissue masses
There can be cross over in presentations, particularly in advanced disease
What are the subtypes of Hodgkin lymphoma
Classical:
-nodular sclerosing
-mixed cellularity
-lymphocyte rich
-lymphocyte depleted
Nodular lymphocyte predominant
What type of lymphoid neoplasm is follicular lymphoma
A peripheral B cell neoplasm
What are the 5 classification groups of lymphoid neoplasms
- Precursor B-cell neoplasms (B-ALL)
- Peripheral B-cell neoplasms
- Precursor T-cell neoplasms (T-ALL)
- Peripheral T-cell neoplasms
- Hodgkin lymphoma
What is the difference between Hodgkin lymphoma and NHL in terms of their typical distribution at diagnosis and pattern of spread
Hodgkin lymphoma sometimes presents in a single group of lymph nodes only.
Tend to spread in an orderly fashion. Lymph nodes, then spleen, then liver, then bone marrow + other tissues
Extranodal presentation is rare. Rare to involve waldeyer ring or mesenteric nodes
NHL more likely to present as disseminated disease and unpredictable
What is included in the waldeyer ring
Adenoid bands
Tubal tonsils ( located posterior to the opening of Eustachian tubes)
Palatine tonsils
Pharyngeal tonsils/band
Lingual tonsils
What cells are characteristic of Hodgkin lymphoma
Reed Sternberg cells: neoplastic giant cells with owl eye appearance
What type of cell are Reed Sternberg cells derived from
Post germinal centre B cells
What makes up most of the cellularity of Hodgkin lymphoma
Lymphocytes, macrophages, granulocytes recruited by reed Sternberg cells
What is the average age of diagnosis of Hodgkin lymphoma
32 years old
Why is nodular lymphocyte predominant Hodgkin lymphoma not considered classical lymphoma
The reed Sternberg cells have a different immunophenotype
Do Reed-sternberg cells commonly express B-cell genes
No, presumably due to widespread epigenetic change
Why is T-cell immune response again Reed-Sternberg cells commonly not effective
Due to increased copy number (therefore expression) of PD-L1 and PD-L2 to inhibit T-cell activation
What is the appearance of Reed-Sternberg cells
Large cells with binucleation
Each nucleus has large inclusion-like nucleoli
Abundant eosinophilic cytoplasm
Prominent nuclear membrane
Perinuclear halo
Multiple variants exist
How is Hodgkin lymphoma distinguished from other conditions that have Reed-Sternbeg-like cells
The presence of Reed-Sternberg cells surrounded by background of non-neoplastic cells (confirmed by IHC)
What is the IHC profile of classical Hodgkin lymphomas
CD15+ CD30+ PAX5+
CD45-
What is the IHC profile of nodular lymphocyte predominant Hodgkin lymphoma
CD20+ BCL6+
CD15- CD30-
What is the most common subtype of Hodgkin lymphoma
Nodular sclerosis (65-70% of cases)
What variant of Reed-Sternberg cells are seen in nodular sclerosis Hodgkin lymphoma
Lacunar cells: nucleus sitting in large empty space (as a result of processing process to produce slides)
What are the microscopic features of nodular sclerosis Hodgkin lymphoma
Lacunar Reed Sternberg cells
Infiltrate of T cells, eosinophils, macrophages, plasma cells
Fibrous bands of collagen deposition resulting in involved lymph nodes being divided up into discrete nodules
Usually EBV -ve
What is PAX5
A B cell transcription factor
What is the prognosis of nodular sclerosis Hodgkin lymphoma
Excellent
How does mixed cellularity Hodgkin lymphoma differ from nodular sclerosis in terms of histological features
Reed Sternberg cells frequent
Commonly EBV +ve
What is the typical clinical presentation of nodular sclerosis Hodgkin lymphoma
Young age
Mediastinal disease common
M=F
What is the typical clinical presentation of mixed cellularity Hodgkin lymphoma
Older age(biphasic young age and middle age)
Present with more advanced stage disease
M>F
Presence of what virus is associated with Hodgkin lymphoma
EBV, varies in rates of positivity depending on subtype
What are the histological features of nodular lymphocyte predominant Hodgkin lymphoma
“Popcorn cells” rather than typical Reed-Sternberg cells
Lymphocyte and macrophage infiltrates
What is the typical presentation of nodular lymphocyte predominant Hodgkin lymphoma
M>F
Young age (<35)
Cervical or axillary lymphadenopathy
Prognosis excellent
What staging system is used for Hodgkin Lymphoma
Ann Arbor staging
-see Robbins page 615
What malignancy appears to be most responsive to immune checkpoint inhibitors
Hodgkin lymphoma
What is the typical presentation of B- acute lymphoblastic lymphoma/leukaemia
Presents as a leukaemia in childhood
What is the typical presentation of acute T-cell acute lymphoblastic leukaemia/lymphoma
Presents as a thymus lymphoma in adolescence
What gene in mutated by chromosomal aberrations in almost all T-cell ALL
NOTCH1
What percentage of ALL have chromosomal abnormalities, and what what is the most common aberration?
90%
Most common is hyperploidy (increased numbers of chromosomes, often >50
What are microscopic features of ALL
Scanty basophilic cytoplasm
Nuclei larger than normal lymphocytes, small nucleoli.
Nuclear membrane frequently subdivided
High mitotic rate
“Starry sky” appearance from macrophages Ingesting apoptotic cells
On immunophenotyping how is ALL distinguished from AML
TdT (terminal deoxynucleotidyl transferase) is expressed only in pre-B and pre-T lymphoblasts
What are the immunophenotypes of immature and more mature B-ALL
Immature: CD19, PAX5,CD10 +/-
More mature: CD10, CD19, CD20, pax5
What are the typical immunophenotypes of very immature and more mature T-ALL
Maturity independent: CD1, CD2, CD5
More mature: CD3, CD4, CD8
What malignancies have the chromosomal 9:22 translocation. What is the resulting gene fusion, and what is the therapeutic relevance
AML and some B-ALLs
Results in BCR-ABL fusion, resulting in constitutional tyrosine kinase activity of ABL.
There is an inhibitor for this fused tyrosine kinase, Imatinib, which dramatically improves survival
What anti apoptotic protein is uniformly over-expressed in CLL (chronic lymphocytic leukaemia).
BCL2
The NOTCH1 receptor frequently has gain of function mutations
What is the microscopic appearance of CLL
Lymph nodes Small lymphocytes with round nuclei and scant cytoplasm
Pathopnemonic: ‘proliferation centres’ containing larger activated lymphocytes
Smudge cells on blood smears of peripheral blood (cells disrupted in process of making smears)
What is the typical immunophenotypes of CLL
CD19, CD20, high levels expression of BCL2
What is the rate of transformation of CLL to high grade lymphoma, and what are common mutations involved
5-10%
P53 and MYC
What chromosomal translocation is a hallmark of follicular lymphoma
14:18
Involves BCL2 gene, leading to over expression of BCL2
What cancers are associated with BCL2 over expression, and by what mechanisms
Follicular lymphoma: chromosomal translocation involving BCL2 gene 14:18
DLBCL: same translocation as follicular lymphoma, in 10-20%
CLL: deletions involving genes that have downstream effects leading to increased expression of BCL2
What are microscopic features of lymph nodes involved by follicular lymphoma
Lack of apoptotic cells in germinal centres
Nodular or diffuse growth pattern
Two cell types:
Centrocytes: small cells with scanty cytoplasm, cleaved/ irregularly contoured nuclei
Centroblasts: larger cells, open nuclear chromatin, several nucleoli, modest cytoplasm
What is the typical immunophenotypes of Follicular lymphoma
Positive: CD20, CD19, CD10, BCL6
Negative: CD5
BCL2 positive (negative in normal germinal centres)
What percentage of follicular lymphomas transform to high grade lymphoma
30-50%
Usually with increased expression of MYC
What are the most common genetic abnormalities in DLBCL
BCL6 translocations with breakage of the BCL6 gene. BCL6 is a transcription depressor (ie tumour suppressor)
t(14:18) involving BCL2 gene. This usually occurs where BCL6 mutation is not present
Sometimes translocations involving MYC
What are the morphological features of DLBCL
Large cell size 4-5x the size of small lymphocytes
Diffuse pattern of growth
Variety of different appearances of nucleus. Most common vesicular appearance to nucleus due to chromatin margination to the nuclear membrane
2-3 nuclei
Moderately abundant cytoplasm
Sometimes nuclei can resemble reed sternberg cells
What is the typical immunophenotypes of DLBCL
Positive: CD19, CD20
Variable: BCL6, CD10, BCL2, MYC
Is Follicular lymphoma or DLBCL more likely to be cured
DLBCL. Follicular treatment is considered palliative from the outset with aggressive chemo not effective, but it is more indolent.
How does MYC translocation affect the prognosis of DLBCL. What is the implication for treatment
Worse prognosis. Some think it should be treated with Burkett lymphoma treatment regimens
What is “double hit” lymphoma
Mutations involving MYC and BCL2 or BCL6
What is triple hit lymphoma
Mutations involving MYC, BCL2 and BCL6
Which tyrosine kinase inhibitor is used against the Philadelphia chromosome
Imatinib
Ie, t(9:22) BCR-ABL in CML and some ALL
What is the general pattern of bone marrow involvement of aggressive vs indolent lymphomas?
Indolent lymphomas more typically involve bone marrow.
Hodgkin lymphoma and DLBCL don’t frequently involve bone marrow
What is the difference between germinal centre and non-germinal centre type DLBCL in terms of IHC profile and prognosis
Germinal centre type has a favourable prognosis
BCL6, CD10 and MUM1 expression determines germinal centre vs non germinal centre
BCL6+, CD10+, MUM1- germinal centre typical expression
CD10- and either MUM1+ or BCL6- non-germinal centre
Translocations of which gene, on which chromosome are always present in Burketts lymphoma
MYC gene on chromosome 8
What are the three main categories of Burkett lymphoma
Endemic (African) (EBV)
Sporadic (non-endemic)
HIV associated
What transcription factor is frequently has increased activity in Burkett lymphoma
E2A (TCF3)
What is the typical microscopic appearance of Burketts lymphoma
Starry sky appearance from apoptotic cells being ingested by macrophages
Medium sized lymphocytes. Coarse chromatin, multiple nucleoli, round/oval nuclei, moderate cytoplasm
What is the typical IHC profile of Burketts lymphoma
Positive: CD19, CD20, BCL6, CD10
Negative: BCL2
What is the typical presentation of Burketts lymphoma
Children and young adults
Extranodal
Mass involving mandible is common
Predilection to involve abdominal viscera
Bone marrow not involved
30% of childhood lymphomas in US.
Most can be cured with intensive chemotherapy
What is the key translocation found in mantle cell lymphoma. What is over expressed as a result
T(11;14) leading to over expression of cyclinD1
Ie promoting G1-S transition
What is the typical microscopic appearance of mantle cell lymphoma
Small lymphocytes surrounding germinal centres in lymph node (which may be atrophic )
What are examples of germinal centre type peripheral B cell lymphomas
Follicular lymphoma
DLBCL (can also be post-germinal centre)
Burkett lymphoma
What is the typical IHC profile of mantle cell lymphoma
Positive: CD20, CD19, CD5, CD23, cyclin D1 over expressed
CD23- in CLL/SLL, helping distinguish this from mantle cell lymphoma
How are marginal zone lymphomas and MALTomas related
MALTomas are a subset of marginal zone lymphomas that arise in extranodal sites
MALT = mucosa associated lymphoid tumours
What type of B cells are the origin of marginal zone lymphomas
Memory B cells
What are 3 typical features of the pathogens is of marginal zone lymphomas
1) They arise within tissues involved by chronic autoimmune/inflammatory disorders (eg Sjogrens, Hashimoto’s thyroiditis, chronic H pylori infection
2) they usually remain localised
3) they can regress when underlying infectious/inflammatory process treated
What is the typical presentation of hairy cell leukaemia
Males predominant 5:1
Median age 55
What is the key mutation found in hairy cell leukaemia
BRAF V600 mutation
What are the microscopic features of hairy cell leukaemia
On phase contrasted microscope examination of peripheral blood smear the cells have a hairy appearance
What is the typical immune profile of hairy cell leukaemia
CD19/CD20 positive
Also positive for other distinctive markers
What is the typical pattern of disease spread of hairy cell leukaemia at presentation
Spleen massively involved (with associated infection)
Liver involved
Bone marrow involvement with marrow displacement resulting in cytopenias
What is the typical disease course and response to treatment of hairy cell leukaemia
Indolent
Excellent response to very gentle chemo, relapses years later, but responsive to further chemo
If resistant to chemo BRAF inhibitors have excellent response
What tyrosine kinase mutation is associated with anaplastic large cell lymphoma (t-cell)
ALK
What is the difference in prognosis of T cell lymphomas derived from NK cells compared to T cells
NK lymphomas are more aggressive
What T cell lymphoma is associated with EBV
Extranodal NK/T cell lymphoma, nasal type
What is the peak age of incidence of multiple myeloma
65-70
What are some of the terms used for proteins produced by myeloma cells
Bence Jones proteins (light chains in urine)
Serum free light chains (kappa or lambda resulting in a misbalance)
What are common mutations in multiple myeloma
Cyclin D, p53. MYC in aggressive forms
What is the immunophenotypes of plasma cell tumours
CD138+, CD38+, MUM1+, CD79a+
Negative: CD19/PAX5
Variable: CD45, CD20, CD56, CD10, CD117
What is the microscopic appearance of plasmacytoma
Normal plasmablasts to bizarre multinucleated cells
Perinuclear clearing due to prominent Golgi apparatus
Cytoplasmic droplets containing immunoglobulin
Amyloid deposits
What are the diagnosis on the spectrum of multiple myeloma
Multiple myeloma (bone marrow plasma cells >10% + disease defining event)
Solitary myeloma (plasmacytoma)
Smoldering myeloma (bone marrow clonal plasma cells 10-30%, no disease defining events
MGUS (serum M protein <3%)
What is Waldenstroms macroglobulinaemia
A hyperviscosity syndrome caused by excessive serum IgM. Eg, caused by lymphoplasmocytic lymphoma
What is the difference between chronic lymphocytic lymphoma and lymphoplasmocytic lymphoma
A substantial fraction of the tumour cells have undergone terminal differentiation into plasma cells
What are the symptoms of Waldenstrom syndrome
Visual impairment
Neurological problems; headache, dizziness, deafness, stupor
Bleeding
Cryoglobulinaemia (coagulation at cold temperatures)
What targeted therapy is used against the abnormal product of the Philadelphia chromosome. Why does disease relapse if treatment is stopped
TKI Imatinib. Very effective because tumours involved display oncogenic addiction because they are dependent on this one mutation.
Disease relapses when treatment stopped because stem cells harbouring mutation are unaffected.
What infections are associated with Burketts lymphoma
EBV (virtually all endemic lymphoma, 15-20% of sporadic lymphoma)
HIV (25% also have EBV)
What virus infection is always present in adult T cell leukaemia/lymphoma
HTLV-1
Endemic in Japan, west Africa, Caribbean.
In plasma cell neoplasms what genes are frequently involved in translocations
IGH 1 on chromosome 14
Cyclin D1 ( chromosome 11)
Cyclin D3 (chromosome 6)
MYC (chromosome 8): more aggressive)
What is the IHC profile of B-cell lymphoblasts
TdT (non-lineage specific), CD34
CD19 (pan b cell marker)
One or more of: CD10, CD79a (others cCD22)
What is the IHC profile of T-cell lymphoblasts
TdT (non-lineage specific), CD34
CD3 (pan t-cell)
Which lymphomas have CD5 positivity
B cell: naive B cells and mantle cell lymphoma
T cell: most T cell lymphomas
Are there any specific IHC markers for marginal zone lymphomas
No. General/pan b-cell markers only.
Positive: CD45, CD19, PAX5, CD79a, CD20
What is the microscopic appearance of Reed Sternberg cells
Binecleated
Prominent nucleoli
Well demarcated nuclear membrane
Eosinophilic cytoplasm
Perinuclear halo
What are risk factors for Hodgkin lymphoma
EBV infection
What is the pattern of age presentation of Hodgkin lymphoma
Bimodal: median 25 and 60-70
What is the relative prognosis of the four types of classical Hodgkin lymphoma
Best: lymphocyte rich HL (less commonly involves mediastinum
Next: Nodular sclerosing HL
Then: Mixed cellularity
Worst: Lymphocyte depleted HL
What are the morphological features of lymph nodes involved by low grade follicular lymphoma
Loss of polarity
Loss or effacement of marginal zone
Centrocytes infiltrating interfolicular areas
How is follicular lymphoma graded
Based on the number of Centro blasts per HPF.
What is the microscopic appearance of grade 3B follicular lymphoma
Solid sheets of centroblasts
What IHC pattern is common in mediastinal DLBCL
CD30 weak positivity in over 80%
MUM1+ in 75%. Ie, majority are non-GC type (unfavourable)
What is the IHC profile of NK/T-cell lymphoma nasal type
Either NK or T-cell phenotype:
NK cells: CD56+/ surface CD3-
T-cells: CD56-/ CD3+
Positive: EBV/EBER, CD45, CD43
Negative: CD4, 5, 8
What is the difference between a DLBCL with double expressor MYC/bcl2 versus double hit
Double/triple hit must be tested for by cytogenetics for rearrangements of the c-MYC, BCL2, BCL6 genes.
IHC testing is not considered a substitute. IHC over expression of c-MYC or BCL2 may or may not be associated with the relevant gene rearrangement
What are poor prognostic factors for primary mediastinal b cell lymphoma
Pleural/ pericardial effusion
Extension beyond mediastinum
B symptoms
Advanced stage
High LDH
Relapse within 1.5 years
Unsatisfactory response to induction
What are the microscopic features of primary mediastinal b cell lymphoma
Medium sized lymphocytes
Round-oval nuclei
Prominent sclerosis
What is the rate of progression of MGUS to multiple myeloma
1% per year
Median time to development of malignancy 10.5 years
What is the rate of progression of smoldering myeloma into multiple myeloma
10% per year
What proportion of solitary plasmacytoma is medullary vs extramedullary
2/3 are bone/medullary
What is the rate of progression of solitary plasmacytoma to multiple myeloma
Almost all will eventually progress
Medullary: 50% at 5 years, 90% at 10 years
Extramedullary: 15% at 5 years, 35% at 10 years
What is the rate of lymph node involvement of extramedullary plasmacytoma
20-40%
What are prognostic factors in multiple myeloma
R-ISS factors (LDH, albumin, B2 macroglobulin, high risk cytogenetics abnormalities)
High CRP
Bone marrow infiltration
Plasma-blastic morphology
What type of lymphoma is mycosis fungoides
Primary cutaneous T cell lymphoma
What is the epidemiological pattern of mycosis fungoides
Peak incidence age 60
M>F
50% of primary cutaneous lymphoma
What types of primary cutaneous b cell lymphomas are most common
Follicular centre lymphoma (lacks 14:18 translocation)
Marginal zone
Primary cutaneous DLBCL
All treated as per their non-cutaneous counterparts
In general, what is the diagnostic system for mycosis fungoides
Diagnosis of exclusion
Clinical diagnosis based on combination of the following:
-clinical
-histo -pathologic
-molecular: TCR gene rearrangement
-IHC
What is the triad of features that characterises sezary syndrome
Circulating neoplastic T cells
Diffuse erythema
Severe disabling pruritis
(+/- lymphadenopathy)
What is the microscopic appearance of mycosis fungoides
Band like papillary dermis infiltration of lymphocytes
Lymphocytes have cerebriform nuclei
What is the typical IHC pattern of atypical cells in mycosis fungoides
CD4+
Loss of CD3, CD5, CD7
What are the types of skin lesions in mycosis fungoides
Patch: no significant induration, not palpable
Plaque: palpable borders, slightly raised, crusted
Tumour: palpable nodule
Erythroderma: >80% body surface area
What is the prognosis of mycosis fungoides
Considered incurable
Early stage: 5yr OS80-95%
Advanced stage: OS 40-60%
What type of transformation of mycosis fungoides is associated with worse outcome
Large cell transformation
Cells 4x size of small lymphocytes, comprising >25% of cell population
What is the typical IHC profile of Ewings sarcoma
CD99+, FLI1+
Negative: S100, NSE, ie does not have neural differentiation. This distinguishes it from PNET
How is response to induction chemotherapy measured in Ewings sarcoma
Grade 1-4 based on % of necrosis
What is the typical clinical presentation of Ewing sarcoma
Presents with localised disease in 75-80%
Pain and swelling
What is the xray appearance of Ewings versus osteosarcoma
Both: Codmans triangle: displaced periosteum with cortical destruction
Ewings: onion skinning. Periostea. Reaction/ layers of reactive bone. More commonly diaphysis
Osteosarcoma: sunburst pattern. More commonly metaphysis
