Hematologic Malignancies Flashcards
What are other names for lymphoma
lymphosarcoma (LSA)
What is one of the most common canine cancers
lymphosarcoma (lymphoma)
What age of dogs typically get lymphoma
6-9 years
cancer of middle-aged dogs (similar age grouping in people)
What canine breeds are at an increased risk for lymphoma
Boxers
Labs
Golden Retrievers
How are lymphomas classified
1) WHO staging
2) Anatomic site
3) Histologic grading
4) Immunophenotype
What is the WHO stagings?
1: Single enlarged lymph node (in) or organ
2) Enlarged regional lymph nodes one one side of diaphragm
3) Generalized peripheral lymphadenopathy *
4) Hepatosplenic involvement*
5) Bone marrow involvement or extranodal sites (e.g ocular, spinal, etc)
Substages
a) asymptomatic (feeling good) - 80%
b) symptomatic (sick) - 20% (more often T cell phenotype)
WHO staging of lymphoma where there is hepatospenic involvement
4
WHO staging of lymphoma where there is a single enlarged lymph node (In) or organ
1
WHO staging of lymphoma where there is bone marrow involvement or extranodal sites (e.g ocular, spinal, etc)
5
WHO staging of lymphoma where there is generalized peripheral lymphadenopathy
3
WHO staging of lymphoma where there is enlarged regional lymph nodes on one side of diaphragm
2
80% of dogs that are stage III or IV and what substage **
A- asymptomatic (feeling g00d)
that means 80% of dogs with generalized peripheral lymphadenopathy and hepatosplenic involvement are asymptomatic
What is substage b for lymphoma
b= symptomatic
20% (more often T cell phenotype_)
80% of lymphoma cases present with what anatomic site
Multicentric (80% of cases)
How might you define lymphoma based on anatomic site
-Multicentric (80%)
-Mediastinal
-Gastrointestinal
-Hepatic
-Cutaneous (epitheliotropic vs non-epitheliotropic)
What are the general two classifications of histologic grading of lymphoma
1) Intermediate to high grade/large cell (lymphoblastic)
-Most common
-Rapid onset of clinical signs
-Needs immediate treatment
2) Low grade (small cell) lymphocytic
-Indolent course: slowly devleoping over months to years
-Long survival- may not require treatment initially
What is the most common histological form of lymphoma
Intermediate to high grade/large cell (lymphoblastic)
-Most common
-Rapid onset of clinical signs
-Needs immediate treatment
What is the difference of lymphoblastic vs lymphocytic lymphoma
lymphoblastic: large cell (high grade)
lymphocytic: small cell (low grade)
Does lymphoblastic or lymphocytic lymphoma have a better survival
Lymphocytic- is slowly developing over months to years, may not require treatment initially
while lymphoblastic has a rapid onset of clinical signs and needs immediate treatment
How is lymphoma classified generally on immunophenotype
B cell vs T cell
What is the most common clinical presentation stage of lymphoma in dogs
Stage 3a
Generalized peripheral lymphadenopathy, no systemic illness
+/-
-hepatosplenomegaly
-lymphocytosis/ monocytosis -> secondary to bone marrow infiltration
-hypercalcemia (more likely associated with T cell phenotype)
Hypercalcemia is more likely associated with what phenotype in dogs
T cell phenotype
if the canine patient has substage b lymphoma, then what clinical signs might you see
1) lethargy
2) hyporexia
3) weight loss
4) vomiting
5) diarrhea
6) PU/PD (hypercalcemia)
What is adequate first wave diagnostic recommendations for canine lymphoma
Cytology is usually adequate for diagnosis- need to submit to lab
1) Cells are larger than neutrophils
2) Absence of plasma cells
3) Homogenous population of large lymphoid cells
What are the cytologic features of LSA
1) Cells are larger than neutrophils
2) Absence of plasma cells
3) Homogenous population of large lymphoid cells
Is cytology enough to diagnose lymphoma
for most canine LSA cases, yes but depends on the species, site, cell size, sample obtained, etc
Canine: diagnostic for intermediate-large cell LSA in 80-90% of cases
When diagnosing LSA, what lymph nodes should you be caution about doing a LN cytology on
Mandibular LN - drains oral cavity, could have a reactive population in there
do popliteal instead if you have it accessible
Cytologic diagnosis of LSA might be difficult in what type
Indolent (small cell) LSA
What should you do if the cytology result is lymphoid hyperplasia vs LSA
biopsy (whole node)
What are the “textbook” diagnostic work up of LSA that you should do but might not feasible
-Cytology to confirm diagnosis
-Routine lab work (CBC/Chem/UA)
-Three view thoracic radiographs
-Immunophenotyping (B vs T cell)
-Bone marrow aspirate / cytology
-Cardiac ultrasound (if using doxorubicin based protocols)
very expensive: can be about 5,000-10,000
What are considerations for diagnostic recommendations for LSA
for many cases, results of staging will not alter treatment options (exception of phenotype in some instititions)
require select staging tests (Ultrasound, chest x-rays) when clinically relevant- clinically ill patient, rule out other issues, on clinical trial
recommend but not rquire staging when not clinically relevant
-save financial resources for treatment
Highly recommended
1) Cytology to confirm diagnosis
2) Routine labwork: CBC/ Chemistry
3) Immunophenotyping
What LSA staging tests are strongly recommended
Highly recommended
1) Cytology to confirm diagnosis
2) Routine labwork: CBC/ Chemistry
3) Immunophenotyping
optional: 3 view thoracic rads, abdominal rads, echocard, bone marrow aspirate/cytllogy, lymph node biopsy to evaluate histopath
In an LSA workup, what are you looking for on the CBC
1) penias - ie. Thrombocytopenia (this gives evidence that the bone marrow is infiltrated
2) Lympocytosis
In an LSA workup, what are you looking for on Chemistry
1) Hypercalcemia (ionized if hypercalcemia)
2) Hyperglobulinemia
3) Azotemia
4) Elevated liver enzymes
In an LSA workup, what are you looking for on thoracic rads
1) mediastinal mass
2) infiltrative pattern (looks like interstitial pattern)
3) lymph node enlargement
in a LSA workup, what might you see when doing abdominal ultrasound
1) Lymphadenopathy
2) Diffuse spleen infiltration (swiss cheese looking)
In dogs, why is immunophenotype important
B is better
T is tougher
changes the prognosis- may affect client decision on treatment
outcome may change treatment recommendations (institution / clinican dependent)
In dogs, what are the characteristics of B cell LSA
1) 2/3 of intermediate-large cell lymphoma cases (most common)
2) Multicentric (multiple enlarged lymphnodes +/- liver/ spleen) most common form
3) Any breed
4) Excellent response (90-95% response to chemotherapy)
5) Good prognosis (median survival time is 12-15 months with CHOP chemotherapy
In dogs, what are the characteristics of T cell LSA
1) 1/3 of intermediate large-large cell lymphoma cases (less common)
2) Predilection Sites: Skin, mediastinum, GI, hepatic
3) Predilection Breeds: Boxer***, Shih Tzu, Australian Shepherd
4) Shorter response to CHOP chemotherapy
5) Poorer response to doxorubicin
6) Average survival time is 4-8 months with chemotherapy
In dogs, the ______ immunophenotype is about 2/3 of intermediate to large cell lymphoma while the ______ immunophenotype is 1/3 of intermediate to large cell lymphoma cases
2/3= B cell
1/3 = T cell
In dogs does B or T cell have a poorer response to Doxorubicin
T cell
How does the survival time with chemotherapy differ between B vs T cell LSA in dogs
B cell: 12 to 15 months with CHOP chemotherapy
T cell: 4-8 months w chemotherapy
What breeds of dogs are predisposed to T cell LSA
Boxer***, Shih Tzu, Australian Shepherd
What are the predilection site for T cell LSA
Skin, mediastinum, GI, hepatic
What are the immunophenotyping tests available for LSA
1) Immunohistochemistry (on histopath tissue) - IHC
2) Immunocytochemistry (cytologic prep)
3) PARR (Cytologic prep)
4) Flow cytometry of lymph node/ organ needle aspirate, peripheral blood (cells in fluid)
IHC needs to be done on
tissue - biopsied in order to do histopath
How is immunocytochemistry doe
special stains performed on cytology samples (cells from needle aspirate)
similar concept as IHC
What is the B cell stain used in ICC and IHC
PAX5
How is flow cytometry performed
monoclonal antibodies labeled with fluorescent markers are applied to cells in suspension
cells in suspension, pass through measuring system (light and detectors) and analyzed based on different characteristics such as the fluorescent label, size, etc.
Sorts the cells into B or T cell and also looks at cell size
What sample type is needed for flow cytometry
Cells in suspension- Blood (if lymphcytosis), FNA, fluid
NOT formalin fixed
Cells must arrive to lab alive (overnight shipping on ice if off site)
What are the benefits of Flow cytometry for LSA
allows for prognostication and classification by identifying
1) Cell size
2) B vs T cell
What are the flow cytometry markers used to identify B cells
CD20
CD21
CD79a
What are the flow cytometry markers used
CD3
CD5
for CD4 or CD8
What is CD45
pan-leukocyte
What is CD34
precursor cells
PCR reaction that amplifies the conserved regions of T cell receptor or immunoglobulin (b cell) genes
PARR (PCR for antigen receptor rearrangement)
What are the benefits of PARR
1) Confirms clonal population of cells (ie cancer, esp if cytology inconclusive)
2) Determines if B or T cell
Cons: Does not differentiate cell size (unlike flow cytometry, this can be a challenge for some forms. e.g diffuse small B cell forms
PARR uses what sample types
glass slide of blood smear, effusion, FNA
cells in suspension, effusion, blood
What are the downsides of using PARR
Does not differentiate cell size (unlike flow cytometry, this can be a challenge for some forms. e.g diffuse small B cell forms
Do flow cytometry or PARR??
-Lymphocytosis (blood)
Do flow cytometry
can tell if small lymphocytes (chronic leukemia) or immature, blasts (acute leukemia)
Do flow cytometry or PARR??
Lymphadenopathy where you know it is lymphoma
Flow cytometry (FNA)
known lymphoma (need to determine the phenotype)
for prognostic information (size)
Do flow cytometry or PARR??
Lymphadenopathy FNA cytology is inconclusive
Do PARR- can help differentiate reactive node vs neoplastic
(not clonal vs clonal population)
Do flow cytometry or PARR??
cavity/effusion/bone marrow aspirate
PARR
it can amplify DNA, this is especially helpful in fluids with a rare number of abnormal lymphoid cells present
Do flow cytometry or PARR??
mediastinal mass
do Flow cytometry to tell if lymphoma or thymoma
What is the gold standard for LSA immunophenotyping
IHC - but this requires a biopsy which is more invasive and more money
Flow cytometry, PARR, ICC is less invasive than biospy when performed via FNA
How does the sensitivity of flow cytometry vs PARR differ in detecting B cell vs T cell lymphoma (compared to IHC= gold standard)
Flow cytometry is better
detects B cells 91% (as opposed to 67% of PARR)
Flow cytometry is better, detects T cell 100%, while PARR 75%
FC and IHC was 94% agreement
while PARR and IHC has 69% agreement
What is the preferred non-invasive method for LSA immunophenotyping
FC- it has 94% agreement with IHC and it characterizes cell size which can also help with prognosis
What test do you do if there is no definitive diagnosis of LSA
PARR to rule in or out clonality
What test do you do for LSA if there is already a biopsy performed
IHC
What should you do if logistically impossible to get flow samples submitted appropriately (seeing a case on Friday afternoon/ over weekend or unable to ship samples overnight to get to lab in time for cells to viable)
PARR
What is a downside to ICC for LSA phenotyping
dont get the cell size characteristic
How is canine LSA treated
1) Chemotherapy ** - standard
2) Radiation therapy- local (nasal) or regional (mediastinum)
3) Surgery- solitary GI lesions causing obstruction, single lymph node/extranodal site (rare)
4) Prednisone only/ palliative care
5) No treatment = rapid progression
What mutation causes increased sensitivity to certain chemotherapy agents
ABCB1 gene
1) Australian Shephard (also mini) 50% frequency
2) Collie - 70% frequency
What is the most chemo-responsive cancer
LSA - 85 to 90% of dogs will experience response
What are the goals of LSA treatment
improved QOL
Reduction in lymph node sizes
prolonged survival time
you should treat because 85-90% of dogs will experience a response
only 25-30% of dogs will have side effects with <5% have life-threatening toxicity
What are the general response rate of treating LSA with chemotherapy
85-90%
multi-agent protocols > single agent protocols
response rate, remission duration and survival vary with protocol (and study and institution)
How does the median remission duration with a multiagent protocol for LSA differ between B cell vs T cell
B cell: 6-8 month remission duration
T cell: 3-6 months remission duration
How does the median survival time with multigaent protocol for LSA differ between B cell vs T cell
B cell: 12-15 months survival
T cell: 4 to 8 months
15-20% of dogs alive at 2 years
10% cured
Complete response to chemotherapy
no evidence of disease
partial response to chemotherapy
> 30% decrease in sum longest diameter compared to baseline sum LD
progressive disease
> 20% increase in sum longest diameter compared to smallest sum longest diameter or baseline, new lesions
stable disease (LSA)
less than 30% decrease or greater than 20% increase in sum longest diameter
What is the best measure of LSA treatment efficacy
Time from start of treatment to relapse
What factors influence the cancer treatment protocol
Patient, client, and clinician factors
What are the 4 drugs in the CHOP protocol, the most common chemotherapy protocol
1) Vincristine
2) Cyclophosphamide
3) Doxorubicin
4) Prednisone
What is the LOPP/MOPP chemotherapy protocol used for
T cell lymphoma at some institutios
What is the LOPP/ MOPP protocol
1) Lomustine or Mustargen
2) Vincristine
3) Procarbazine
4) Prednisone
Rank the canine LSA stages by prognosis
I/II > III/IV > V
Does substage a or b LSA have a better prognosis
A
Does canine B cell or T cell LSA have a better prognosis
B cell > T cell
exception indolent T cell lymphomas
Pretreatment of LSA with prednisone prior to starting chemotherapy may cause
chemotherapy resistance through upregulation of p-gycoprotein pump
What are the 8 prognostic factors of canine LSA *
1) Stage: 1+2 > 3+4> 5
2) Substage: a>b
3) B cell > T cell (except indolent T cell lymphoma
4) Hypercalcemia is poor (T cell)
5) Location: primary hepatic, GI = poor (often T cell)
6) Treatment chosen (steroids alone vs chemotherapy)
7) Pretreatment w prednisone prior to chemotherapy
8) many others, individual response to treatment, etc.
Most dogs with LSA present as
intermediate-large cell
multicentric
B cell
stage 3-4
substage a
what is the prevalence of indolent LSA
estimated 5-30% but unknown
Indolent LSA occurs in what type of dogs
Middle-aged to older dogs
Indolent LSA affects what breeds most likely
Golden Retriever overrepresented in many studies
T/F: indolent LSA has hypercalcemia
False- no hypercalcemia even with T- cell
How does indolent LSA typically present
often mild lymphadenopathy
-often Stage I-II (mandibular +/- superficial cervical lymph nodes)
-incidental finding
-slowly progressive
With indolent LSA, what do you see on cytology
Hand-mirror morphology sometimes
but cytology alone may not be sufficient to confirm the diagnosis
How do you diagnose indolent LSA
1) Cytology may not be sufficient (may see hand-mirror morphology
2) Flow cytometry can be helpful in diagnosis of T zone LSA
3) ** Whole lymph node biopsy +/- immunohistochemistry if flow cytometry is not helpful and you suspect indolent LSA
What is the most common form of indolent LSA
T zone LSA- flow cytometry diagnosis
What are the types of of indolent LSA
B cell types
1) Marginal Zone LSA
2) Follicular LSA
3) Mantle cell LSA
T cell types
1) T zone LSA (most common form of indolent LSA)
If indolent LSA is solitary, treat with
Surgical removal
-Lymph node
may provide long term control if indolent
If indolent LSA is multicentric then treat by
Due to slow clinical course, can often hold on starting chemotherapy until
1) clinical signs develop related to enlarged lymph nodes or internal organ involvement
2) Cytopenia develop (ie neutropenia, thrombocytopenia, etc)
3) Lymphocytes >30k-60k
Treatment recommended is less intesive chemo protocol
-Prednisone with chlorambucil (oral chemotherapy)
If multicentric indolent LSA, you can hold off on treating until
1) clinical signs develop related to enlarged lymph nodes or internal organ involvement
2) Cytopenia develop (ie neutropenia, thrombocytopenia, etc)
3) Lymphocytes >30k-60k
What is the treatment for indolent multicentric LSA
Prednisone with chlorambucil (oral chemotherapy)
What is the most common form of feline lymphoma
alimentary / GI lymphoma
EATCL type II (small cell GI LSA)
How did vaccination change FeLV and lymphoma prevalence in cats
Before 1980: average age at diagnosis is 4-6 years
70% FeLV positive
lesions often mediastinal and spinall
After 1980: 11 years average age diagnosis, 25% FeLV positive
lesion locations more often are GI located
What causes lymphoma in cats in the post - FeLV era
1) Exposure to tobacco smoke - 3x increased risk with >5 year exposure
2) FIV infection, 5x increased risk if FIV+
3) Chronic inflammation
IBD -> GI LSA, nasal lymphoma
4) Diet and GI LSA
For cats, what are the 3 WHO classifications of LSA
a) Enteropathy- associated T cell LSA Type II
b) Enteropathy- associated T cell LSA Type I
c) B cell tumors
Enteropathy- associated T cell LSA Type II occurs most often where
small intestine
Enteropathy- associated T cell LSA characteristics
Most common form of LSA in cats
often occurs in small intestines
T cell phenotype
95% small lymphocytes (ie normal appearing lymphocytes that are more numerous than typical)
Indolent clinical course: prolonged survival time 2.5-3 years with treatment (chlorambucil/steroids)
Another name for Enteropathy- associated T cell LSA Type II
small cell GI LSA
Another name for Enteropathy- associated T cell LSA Type I
large cell GI LSA
What are the characteristics of Enteropathy- associated T cell LSA Type I
Small intestine
T cell
60% large lymphoid cells - 80% of these are large granular lymphomas (LGL)
aggressive form: median survival time 1.5 months with chemotherapy
Does Enteropathy- associated T cell LSA Type I or Type II have a worse prognosis
Type 1: aggressive form with 1.5 month survival time with treatment as opposed to 2.5-3 years with treatment (Type II)
What are the characteristics of B cell tumors in cats
often occurs as multiple tumors throughout GI tract (stomach, small intestine and ileocecocolic junction)
large lymphoid cells
aggressive form: median survival time of 3.5 months with chemotherapy
In cats, B cell tumors typically occur where
often occurs as multiple tumors throughout GI tract (stomach, small intestine and ileocecocolic junction)
How is EATCL type II (small cell GI LSA) in cats treated
Chloroambucil/ pred
prolonged survival time 2.5-3 years with treatment
What are the clinical signs of feline large cell LSA (Type I or B cell)
Acute onset (days to weeks) with acute progression
-Diarrhea
-Vomiting
-Hyporexia/ anorexia
-Weight loss
What are the clinical signs of feline small cell LSA (Type 2)
Chronic intermittent signs
-Months to years: diarrhea, vomiting
-Week to months: hyporexia and weight loss
a lot of clinical overlap with inflammatory bowel disease
How do you work up feline LSA cases
-CBC/CHEM/ UA
-+/- FELV/ FIV test (for cases with acute onset of signs, ie large cell cases
For feline LSA is abdominal ultrasound or radiogrpahs preferred
ultrasound
-can pick up infiltration into the spleen
radiograph might pick up some mediastinal mass or effusion with large cell but often normal with small cell
For feline small cell (type 2) LSA, what would you see on abdominal U/S findings
+/- mild diffuse thickening of the intestines
+/- mild abdominal lymphadenopathy
+/- mass effect in GI tract (less common)
For feline large cell (type 2 or B cell ) LSA, what would you see on abdominal U/S findings
Focal mass effect in stomach, intestine, ileocecocolic junction
enlarged abdominal lymph nodes
+/- effusion
+/- involvement of other organs (renal, spleen, liver, etc)
T/F: LSA phenotype impacts prognosis in cats
False
you might not need to do flow cytometry or PARR
consider theses tests if equivocal cytology
How do you diagnose large cell LSA (Type I or B cell)
1) Abdominal ultrasound
2) Ultrasound guided FNA of abnormal organs/masses
3) Cytology of FNA samples
Why is it difficult to get a confirmed diagnosis of feline small cell (Type 2) LSA
-small cell (normal appearing lymphocyte, making cytology difficult to interpret
-clinical overlap with inflammatory bowel disease making differentiating using ultrasound alone difficult (mild thickening GI, +/- abdominal lymphadenopathy
-minimal/mild changes on abdominal ultrasound not amenable to sampling / non diagnostic samples obtained
diagnostics often needed after abdominal ultrasound include: endoscopy with biopsies, histopathology, immunohistochemistry, and PARR (to differentiate IBD and small cell GI lymphoma)
How can you differentiate feline IBD from small cell LSA **
IHC paired with PARR on histopathology samples can enhance ability to detect malignancy in endoscopic biopsy samples
How do you treat feline small cell (type 2) LSA
less intensive treatment
chlorambucil and prednisolone
(oral chemotherapy, continuous/long term tx)
GI supportive care:
a) Novel protein diet (reduce inflammation)
b) B12 supplement (SQ injections), if indicated
How do you treat feline large cell LSA (Type I or B cell)
More intensive treatment
multi-agent chemotherapy (CHOP)
single agent chemotherapy (doxorubicin, CCNU, etc.)
palliative prednisolone
What is the prognosis of feline small cell (type 2) LSA
90% respond to treatment (chlorambucil/pred) with a median survival time of 2.5-3 years
some may experience long remission and can taper off steroids after 1-2 years of continuous treatment
some may develop more aggressive forms of LSA overtime
What is the prognosis of feline large cell (Type 1 or B cell) LSA
dependent on treatment chosen and response
75% response with 50% responders MST 6-8 months; 25% responders MST 12 months or longer
25% no response to chemotreatment <4-6 weeks survival
Steroids alone = 1 to 2 months
What are prognostic factos of LSA in cats
FELV/FIV = poor
mediastinal, CNS, or renal location = poorer prognosis
nasal = better prognosis (can treat with radiation)
treatment choses chemotherapy»_space;> steroids alone
tumor response to treatment
