Diseases of the Lymph Node Flashcards
1
Q
what causes lymphadenomegaly in cats?
A
yersinia pestis- plague!
natural cycle between rodents and fleas
eating infected animal or bite by infected flea
rapid progression, and zoonotic!
1
Q
multiple myeloma is a neoplasia involving proliferation of what cell type?
A
plasma cells
2
Q
definition of lymphoma
A
heterogenous group of malignancies arising from lymphocytes
3
Q
what are characteristics that define types of lymphoma?
A
- anatomic location: multicentric (mult nodes affected), alimentary (B&T cells in GI becoming neoplastic), mediastinal, cutaneous etc
- cellular origin: B vs T vs precursor. cellular morphology: nuclear size, cellular features
- histologic pattern: diffuse vs nodular
- biologic behavior: indolent vs aggressive
4
Q
what is an indolent tumor?
A
a low-grade tumor
opposite of aggressive/high grade
5
Q
how is cytology useful for diagnosing lymphoma?
A
- initial step, but not last!
- NO SUBTYPING OR PROGNOSIS
- immunocytochemistry available
without architecture, cannot provide subtype
5
Q
what are clinical signs of lymphoma?
A
- generalized lymphadenopathy
- thickened intestine, hepatomegaly, splenomegaly
- advanced disease (BM, aspiration needed)
- mild-moderate nonregenerative anemia common
- lymphopenia/lymphocytosis
- hypercalcemia (mediastinal involvement & thymus)
- hyperglobulinemia: plasma cell tumors and B cell tumors
6
Q
T/F: for a case where you want to differentiate between types of neoplastic cells, cytology is a good diagnostic to use
A
false- does not subtype or give prognosis
7
Q
you want a prognosis diagnostic test for a patient with cancer. what tests are you NOT going to use?
A
- cytology
- PARR
both do not give prognosis. PARR does give diagnosis though
8
Q
what is flow cytometry useful for?
A
SUBTYPING AND PROGNOSIS
samples must be viable; need fresh sample!
9
Q
what is the 1 downside of flow cytometry?
A
need fresh sample
10
Q
T/F: flow cytometry will give you both diagnosis and prognosis
A
true
11
Q
what is histopathology used for?
A
WHO classification system for subtyping and prognosis (with IHC)
invasive procedure
12
Q
what are the downsides to IHC?
A
invasive procedure
13
Q
T/F: histopathology (IHC) will give you both diagnosis and prognosis
A
true
14
Q
what is PCR for antigen receptor rearrangements good for? (PARR)
A
- diagnosis but NOT PROGNOSIS
can be performed on cytology, histology, and non-viable samples
15
Q
what are pros and cons of PARR?
A
doesn’t give prognosis
can be performed on virtually anything- cytology, histology, non-viable samples
16
Q
flow cytometry basics
A
- great non-invasive method for peripheral lymphadenopathy and suspicion of lymphoma (cytology)
- typically need significant neoplastic pop’ln in sample
- can be very sensitive in neoplasia with aberrant antigen expression
- CELLS MUST BE VIABLE
- samples can be peripheral blood, lymph node, tissue aspirates
- some types need IHC for subtyping
17
Q
classification of a tumor requires ___________-
A
immunohistochemistry
18
Q
how does IHC grading work?
A
- diffuse vs nodular
- cell size: large, intermediate, small
- phenotype: B cell tumors, T cell tumors
19
Q
lymph node biopsy pros/cons
A
- often can provide diagnosis, but cannot subtype
- tru cut biopsies not ideal for architecture but 2mm may be fine
- avoid compression of the tissue! artifact crush
- impression smears: keep away from formalin!
- prompt transfer to fixative: mitotic activity can be 40% decreased with >12 hr delay
- can nick the capsule or incise node for better fixation
20
Q
what are 5 types of lymphoma in dogs?
A
- multicentric
- enteric lymphoma
- cutaneous lymphoma
- thymic lymphoma
- splenic lymphoma
21
Q
multicentric lymphoma
A
- peripheral lymph nodes enlarged
- diffuse large B cell most common
- small B cell lymphoma, PTCL, TZL other common subtypes
diagnose with FLOW CYTOMETRY
21
Q
enteric lymphoma
A
- T cell origin, small and large
- colonic, large cell, B cell
diagnose with HISTOPATH
22
cutaneous lymphoma
- cutaneous epitheliotropic T cell lymphoma most common
diagnose by HISTOPATH
23
thymic lymphoma
T cell most common, acute leukemia and PTCL can have mediastinal involvement
aspirate, do FLOW CYTOMETRY
24
splenic lymphoma
splenic marginal zone lymphoma most common
good prognosis
likely need HISTOPATH
25
what doing PARR, what are you looking at?
looking at DNA- don't need viable cell. primers ID areas of rearrangement. reactive processes have variable sized gene rearrangements
26
you run PARR on a dog that presents with generalized lymphadenomegaly. the result comes back as polyclonal. is this dog's lymph node that you sampled reactive or neoplastic?
reactive: variety of rearrangements
27
PARR is used on what sample types and can diagnose what?
- variety of sample types: old, non-viable flow sample, cytology, histology
- diagnosis: distinguishes between neoplasia and hyperplasia/reactive processes
- sensitive in sample without a significant neoplastic process
- NO PROGNOSTIC INFORMATION
28
you want to distinguish a sample between neoplasia and hyperplasia/reactive. what test are you going to run?
PARR
but it doesn't give prognostic information!
29
A 10 year old Golden retriever (Sydney) presents with mandibular lymphadenopathy
* On cytology there is an expansion of intermediate sized lymphocytes. The expansion is concerning for lymphoid neoplasia but not diagnostic.
The dog lives far away and you only got aspirates for cytology. What test can you use with the sample you have to determine if the intermediate sized cells are reactive or neoplastic?
PCR for antigen receptor rearrangements
30
* Aspirate from an enlarged lymph node in the dog reveals there is an expanded population of intermediate sized lymphocytes. Differentials include reactive hyperplasia and lymphoid neoplasia. You decide to perform PARR on a cytology slide. The results indicate there is a clonal T cell population. Are you done with the diagnosis?
NO- could be TZL or PTCL, which have very different prognoses! getting a T cell doesn't mean you have a diagnosis. you need to follow up with flow cytometry.
31
what has a better prognosis, T Zone Lymphoma or Peripheral T cell lymphoma?
TZL: 600->1000
PTCL: <200
32
what are 3 types of lymphoma in cats?
1. enteric lymphoma (most common)
2. thymic lymphoma
3. hodgkin's like lymphoma
less common are nasal and renal
33
what is the most common type of lymphoma in cats?
enteric lymphoma
34
enteric lymphoma in cats
- most common lymphoma in cats. 3 types
1. small mucosal epitheliotropic T cell lymphoma: small intestine, good prognosis, most common type
2. large T cell transmural, poor prognosis
3. large B cell in stomach and large intestine, poor prognosis
35
of all the enteric lymphomas of cats, what one is the one you would want your cat to get?
small mucosal epitheliotropic T cell
small intestine, good prognosis (28 months), most common type
36
what is the most common type of enteric lymphoma in cats?
small mucosal epitheliotropic T cell lymphoma
good prognosis! the others don't have good prognosis
37
thymic lymphoma in cats
- younger age, associated with FeLV
- multicentric uncommon; often associated with FeLV or FIV
38
what lymphoma is associated with FeLV/FIV?
thymic lymphoma
younger age
39
thymic lymphoma is associated with what diseases in cats?
FeLV/FIV
40
hodgkin's like lymphoma in cats
cervical lymphadenopathy, poor characterization of prognosis but may be indolent (causing little/no pain)
41
what species gets t cell rich large B cell lymphoma?
horses
cutaneous, but GI lymphoma can also cause a wasting syndrome
42
An owner of backyard chickens brings two birds in for necropsy
* The birds are 16 weeks of age
* They were walking “funny”
* There are multiple tan-white bulging masses effacing the kidney
what are your 2 differentials?
1. marek's disease
2. lymphoid leukosis
42
what type of lymphoma do horses get?
T cell rich large B cell lymphoma
cutaneous; GI lymphoma can also cause a wasting syndrome
43
what 2 diseases can cause lymphoma in chickens?
marek's disease
lymphoid leukosis
44
marek's disease
- gallid alphaherpesvirus 2
- highly contagious, matures in epithelium of feather follicle. often spread by dander
- enlarged peripheral nerves** look at one side vs other!
- diffuse or nodular lymphoid tumors
45
lymphoid leukosis
- chicken lymphoma
- retrovirus
****BURSA OF FABRICUS USUALLY INVOLVED
46
what is the bursa of fabricus?
The bursa of Fabricius is a primary lymphoid organ in birds that is responsible for the amplification and differentiation of B lymphoid progenitors within its follicular micro environment.
47
neoplastic involvement of the bursa of fabricus is usually involved in what neoplastic disease of birds
lymphoid leukosis- retrovirus
48
how does marek's disease present? how do they get it?
- presents with unilateral paralysis
- tumors can be in heart, ovary, liver, lung, kidney, eyes, feather follicles, nervous system
- highly contagious: bird-bird, contaminated soil, clothes, equipment, dust and dander, aerosol
49
Which is correct about Bovine Leukosis Virus
* A) Animals are usually less than 2 years of age at presentation
* B) This disease is caused by a corona virus
* C) Less than 5% of infected cattle will develop lymphoid neoplasia
* D) There is no way to prevent disease
C: less than 5% of infected cattle with develop lymphoid neoplasia
animals are usually OVER 2, disease is caused by a retro virus, and husbandry is how you prevent it
49
5 year-old Holstein cow
* Poor appetite and melena
* Physical exam:
* Reduction in skin turgor – 2-5% dehydrated
* Rectal temp 38.5 C (101.5 F)
* Rectal palpation – distended rumen, feces dark color, + for occult blood
* CBC/CHEM and was within normal limits
necropsy finds markedly thickened abomasum mucosa
what is your differential?
BLV: bovine leukosis virus
50
what disease is known for causing lymphoma in cattle?
BLV- bovine leukosis virus
51
BLV associated lymphoma in cattle
- enzootic lymphoma caused by retrovirus, disease is B cell phenotype
- 30% of cattle infected will have non-neoplastic persistent lymphocytosis
- less than 5% will develop lymphoma
- more common in adult dairy cattle
52
what are the most common sites of BLV associated lymphoma?
lymph nodes, abomasum, uterus and heart (HULA), retro-orbital, renal and spinal cord, stomach
53
how do you treat BLV associated lymphoma? how do they get it?
- no viable treatment
- limit transfer of infected lymphs
- eradication protocols
- prevent exposure of BLOOD!
54
how can you prevent exposure of blood in cows? what are you preventing by doing this?
preventing BLV- lymphoma
* Do not feed bloody milk to calves
* Cautery can be used for dehorning and disinfect equipment for castration, tattooing or implanting between animals
* Change rectal sleeves between cows
* Clean maternity and calving pens
* Control flies
* Screen blood donors
54
what are lymphomas in cattle not associated with BLV? (sporadic)
1. thymic disease: <2 yrs, respiratory distress
2. multicentric disease: 3-6 months, liver, spleen, kidney, BM involvement
3. cutaneous: 1-3 years, plaques
55
where do carcinomas typically metastasize?
regional lymph nodes thru lymphatic cells
56
where do mast cell tumors and malignant melanomas frequently metastasize to?
lymph nodes
57
where do sarcomas metastasize to?
hematogenously
58
You perform an aspirate on a dog with an enlarged lymph node. There is an expansion of monotonous lymphocytes. Which statement is correct regarding the next possible step for diagnosis.
A) PARR will provide both diagnosis and prognosis for disease
B) Flow cytometry can be preformed on the cytology slides
C) Cytologic diagnosis will provide enough information to prognosticate
D) Flow cytometry can provide both diagnosis and prognosis
D- flow cytometry can provide both diagnosis and prognosis
