Exam # 3 - Final Flashcards
What is hypertrophic osteopathy? What is it a sign of? What occurs? What clinical signs may you see in a patient?
• Hypertrophic osteopathy
◦ Paraneoplastic syndome related to space occupying lesion in the thorax
◦ You will see proliferation of bone in the periosteum. Usually the dog will appear painful with lameness and swollen limbs. Particularly occurs in the long bones.
What is one way to diagnose Psittacosis? What is the most ideal way to diagnose it?
You can do a gram stain to see if it is a gram negative bacteria. Since you cant differentiate it from another gram negative bacteria you should use, machiavelli stain, since the elementary bodies will apear a periwinkle color. To be 100% sure you must use IHC or In situ hybridization.
What are permenant, quiescent/ stable, continous/ cycling labile cells?
- Permenant: no longer replication/ regenerating
- Quiescent stable cells: sometomes regeneration
- Continious cycling labile cells -> consistently regenerating/ replaced
• there are checkpoints at various segments of mitosis.
What is the route of transmission for avian pox?
Transmission:
- Insect bites, skin lacerations
What is the common name for psittacosis?
Pirates disease
What is gastric carcinoma? What can be seen in tumors of this kind? Where do these tumors arise from, who is it common in? What tissue is involved in this? Ect?
- Large animals also get tumors.
- Gastric carcinoma: arrises from esophageal region of gastric mucosa. It is not uncommon in horses.
- This area is lined with stratified squamous epithelium. (Squamous cell carcinoma) Causes ulcerations, proliferatice lesions, ect)
- Infiltrative to tissue so areas of this stomach would be thickened.
What is the likely cause of this lesion?
Canine TVT
What is seen in this image? What is the large dark puple area in the upper left corner? What are the small dots surrounding the large cell?
This is a fibroblast with lymphocystis. It is up to a million times larger than normal. The fibroblast keeps growing and growing.
The small dots are the nuclei of normal sized cells. The large dark purple area is the nucleus of the infected cell.
What is the strongest argument for immune survailences role in cancer? Are the survailence mechanisms as effective as they should be?
- The increase incidence of cancer in immuno-suppressed people
and animals is the strongest argument for the existence of tumor
immune surveillance.
• Unfortunately tumor immune surveillance mechanisms are not as
effective as they should be. The reason is that tumor cells have the
capability to develop mechanisms to evade the immune system of
the immunocompetent host.
Where is it difficult to import from due to concerns for BSE?
Alberta Canada.
ALSO IMPORTANT
What is paraesthesia?
Paresthesia: abnormal sensation of the
skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause.
What stain is depicted here for this gram negative bacteria? What is the bacteria and what can be seen in this image?
Machiavelli stain - you will see elementary bodies staining a fuschia color. This is psittacosis.
How do prions cause metabolic dysfunction of neurons/ neural cells?
- Conversion of normal Prpc to PrPSc
- Accumulation of protease-resistant β-sheet isoform of PrPSc
in short -> changes normal protein to prion protien/ mutated protein.
What is carcinogenesis?
Carcinogenesis is a multistep process at both the phenotypic and genetic level -> tumor progression.
What is the transmission route of psittacosis? What is important about the bacteria in the environment. What kind of disease can it cause in humans?
Transmission:
- Via respiratory droplets, feather dust,
feces
- Inhalation, ingestion or mucosal
(conjunctival) contact
-Survives desiccation
In humans Respiratory disease may be severe, even if you are not immunocompromised you can get bad pneumonia.
What can paraneoplastic syndromes indicate in patients? Why are they important?
- They may represent the earliest manifestation of an occult neoplasm.
– In affected patients they may represent significant clinical problems
and may even be lethal.
What is a way they can treat Canine TVT?
- usually surgically
- Now treating with vincristine.
What is differentiation/ anaplasia?
a) Differentiation/ Anaplasia
“ Refers to the extend to which parenchymal cells resemble the correspondent normal parenchymal cells, both morphologically & functionally
“ Benign tumors are well -differentiated
“ Malignant neoplasms can be well - differentiated or undifferentiated (the latter are said to be “anaplastic”).
What are the steps of change from normal protein to prion protein?
Explaination corresponds to the image attached with numbers indicating the steps.
1.) Prion protein looks similar but is slightly different. Slightly different in a way that makes the protein useless. “ kinda similar, but kinda useless”
2 .) and 3.) Prion interaction begins to cause normal protein to change shape and replicate as the useless prion protein.
3.) This useless protein begins to accumulate in the cytoplasm. You cannot get rid of it.
Essentially a buld up of alot of useless protein and loss of function of normal protein.
What is grading of tumors? What are they classified by? And why is it useful?
• Grading: Gives a semi-quantitative evaluation of the degree of
differentiation of the tumor. Cancers are classified from I to IV with
increasing anaplasia.
• Although histologic grading is useful, histologic appearance not always correlates with biologic behavior.
What is the morphologic diagnosis of these images?
Etiologic diagnosis?
Disease name?
Morphologic diagnosis: Acute severe diffuse necrotizing/ proliferative dermatitis
What species can get chronic wasting disease? Is this a wild animal problem?
White tailed Deer, Mule Deer and Moose.
Can be found in captive and domestic species.
What are the diffences between benign and malignant tumors in the following categories?
- Differentiation
- Growth rate
- Local invasion
- Metastisis
Differentiation
Benign: Well differentiated morphologic features and function. Structure similar to tissue of origin, little or no anaplasia.
Malignant: Poorly differentiated, morphologic features and function. Tissue of origin sometimes unclear. Variable degrees of anaplasia
Growth Rate
Benign: Slow, progressive, expansion, rare mitotic figures, notmal mitotic figures, little necrosis.
Malignant: Rapid growth, frequent mitotic figures, abnormal mitotic figures, necrosis if poor blood supply.
Local Invasion
Benign: No invasion, cohesisve and expansile growth. Capsule often present
Malignant: Local infiltrative growth, capsule often absent or incomplete
Metastisis
Benign: No metastisis
Malignant: Metastasis sometimes present.
What is tumor heterogeneity?
• Generated during tumor growth
◦ By progressive accumulation of heritable changes in tumor cells
• Generation of
◦ subclones &
◦ successful subclones
• can give rise to cells that can become metastatic.
Can tumors be emboli?
Yes, tumors can induce proliferation of fibroblastic tissue and can travel via lymphatics/ vascular tissue to distant areas of the body.
What are teratomas? Is it a mixed tumor? Where can they be seen? Are they benign or malignant?
• Teratomas - usually in horses/ young animals
◦ Usually is incidental finding.
◦ You can find teeth, hair, cartilage ect in this mass within the testicle. They arise from totipotent germ cells.
◦ Occasionally you can find it in the ovaries of mares.
What is the morphologic diagnosis of this histological slide? What is a likely etiologic diagnosis?
Acute severe heterophilic necrotizing multifocal hepatitis
Etiological diagnosis: Bacterial hepatitis
What is likely the cause of this lesion?
Canine TVT
The image on the left is an image of the lymph node of the cat that the subsection of mammary tissue is from? Wjat can be seen with the blue arrow?
- Sample of regional lymph node was taken as well to look for metastasis.
- Arrow points to areas of lymphatic metastisis.
- 90% of tumors in cats are malignant
What is a concern for lymphocystis that can change the prognosis?
The presence of secondary bacterial infections.
What is involved in the staging of a tumor? Which is more helpful, staging or grading?
• Staging: It is based on the size of the primary tumor, its extend of
spread to regional lymph nodes, and the presence or absence of
hematogenous metastases.
• Staging from a clinical point of view has proved to be more useful than grading.
What are the 8 changes in cell
physiology that together determine malignant phenotype?
- Self-sufficiency in growth signals (continue to grow)
- Insensitivity to growth-inhibitory signals (dont respond to inhibitory signals)
- Evasion of apoptosis (can avoid apoptosis)
- Defects in DNA repair
- Limitless replicative potential
- Sustained angiogenesis
- Ability to invade and metastasize
- Ability to escape from immunity and rejection
What animals are at risk of transmissable veneral tumors? What kind of disease is this? What is its route of transmission.
Strays/ dogs allowed to roam, mostly in southern US/ Mexico. Not very common in north america.
Route of transmission: Sexual transmission
STD.
What are characteristics of normal avian skin?
- Normal avian skin (thin)
- Keratinized
- Basement membrane -> 3-4 layers of epidermal skin -> and stratum corneum
What are the differential diagnosis’ to rule out with hypercalcemia?
hyperparathyroid, renal failure, hypoadrenocorticism, hypervitaminosis D
What kind of virus is avian pox?
Genus Avipoxvirus of the Poxviridae
- DS DNA enveloped
What occurs to the cells in lymphicystis? What kind of inflammation is present?
Non suppurative inflammation, lymphoplasmacytic
Eventual cell death, can infect adjacent cells.
Has macrophage/ lymphocyte inflammation.
What are the main signs of lymphocystis?
- Cytomegaly - cell enlargement
- Karyomegaly -> nucleus enlargement
What can occur in lymphocystis if the fish does not die from complications associated from the lesion?
It will either remain the same or eventually regress.
What is the brown around this cell indicating? What kind of stain is this? What is it usually used in?
This is IHC. The brown is the target which shows your histology is positive. This is positive for psittacosis.
How many chromosomes do the normal host cells have in dogs with TVT? What about in the neoplasia cell? What kind of transfer is occuring with this tumor? What is the likely cell type?
- 59 chromosomes in neoplastic cell. vs 78 in normal dog cells
- It is transfered via xenograft, and is proably histiocytic.
What are signs of hypercalcemia?
- Muscle weakness
- Cardiac arrhythmia (rare)
- anorexia
- Vomiting
- Renal Failure
- Polyuria/ polydipsia
What kind of bacteria is Chlamydophila (Chlamydia) psittaci? How does it survive?
- Gram (-) bacterium
- Obligate intracellular (depends on the host’s ATP)
Needs hosts ATP to proliferate.
What is seen in this image? What is the cause?
- Mechanical damage can cause hemorrhage/ ulceration. This is from avian pox (dry) (cutaneous form)
Is there transcoelimic spread in this image?
- Peritoneal implantation (transcoelomic spreading -> peritoneal carcinomatosis
- Nodules attached to the mesentary.
What is occuring in this image?
• Multifocal tumor - can be primary or metastatic ( that arrised from somewhere else and then eventually made it to the liver tissue). This is a pancreatic carcinoma that spread to liver tissue
What are the characteristics of successful subclones?
· high proliferative rate,
· evade host immune response,
· can stimulate development of independent blood supply,
· are independent of exogenous growth factors,
· can spread to distant sites
Why is the accumulation of prions so problematic?
No one knows exactly why it is such a big deal. It is alot of accumulated prion protein “ not goof to have alot of junk in your cytoplasm” and a loss of the needed proteins.
What are the names of the malignant and benign tumors of epithelial origin?
- Squamous epithelial cell
- Adenexal cells
- Melanocyte
- Transitional epithelium
- Uterine columnar epithelium
- Lining of glands/ ducts
- Hepatocyte
- Renal tubular cell
- sertoli cell
- germ cell ( testicle)
- stromal cell ( ovary)
- Germ cell (ovary)
What are epigenetic changes? What else are seen in tumor cells aside from epigenetic changes?
Epigenetic changes: Refers to heritable changes in gene expression in somatic cells resulting from something other than a change in the DNA sequence (most common ones are DNA methylation and histone modification)”.
• DNA mutations, epigenetic changes & chromosomal alterations are also observed in tumor cells.
Some people have genetic predisposition to cancer
Epigenetic changes- No DNA damage but, molecular changes can alter some functions of the tumor.
What is diptheric membranes?
They are the term used to describe necrosis of the lumen of a tubular organ.
What is occuring in this image? What is the way its appearing called? What could occur as a potential side effect or issue with this kind of neoplasm?
- Benign tumor: lipoma, common in mesentary of most horses.
- Usually pedunculated, doesnt produce any clinical problems, but dependent on location it can change if it results in clinical sings/ death.
- If lipoma twists around the peduncle, it could cause ischemic damage or necrosis of the lipoma, and this could cause issues.
- If the lipoma is large enough/ the peduncle has enough give it is possible that the peduncle may wrap around intestines and can cause volvulus.
What is evident in this section of gastric tissue? What is circled by this red circle?
- these areas of blue are mucous secreting neoplastic epithelial cells, characterized by bluish foamy cytoplasm, infiltrate the muscle layer of the stomach.
- The morphology is similar to goblet cells. These are the cells that became neoplastic, which infiltrated the wall of the stomach.
- This is mucinous gastric carcinoma.
What are undifferentiated tumors?
- undifferentiated tumors
- Mixed tumors (multiple cell types derived from a single or multiple germ cell layer - pluripotential or totipotential.
What is anaplasia usually characterized by?
- pleomorphism- different shape
- abnormal nuclear morphology
- high mitotic rate
- loss polarity (disorganization)
Why is psittacosis significant? What Birds are known to be the highest infected?
- Zoonotic disease
- May be fatal in immunocompromised
- Pigeons are highest reported, followed by raptors.
What are the preneoplastic changes? Why is mitotic division very important to the neoplasticity of a cell? What happens if you take out the inciting agent that induce the preneoplastic change?
Preneoplastic changes:
Hyperplasia, metaplasia, dysplasia
Hypertrophy can be considered preneoplastic change.
• Mitotic division is very important to the neoplasticity of a cell. If the cell is rapidly dividing, their is more chance of DNA damage and if they are allowed to replicate, eventually they can aquire the ability to proliferate outside the growth capacity.
If you can take out inciting agent that is inducing this preneoplastic changes than things should be fine, but it is not always.
What is the cause of the lesion seen in this image?
Lymphocystis
What are the advantages of using immunohistochemistry in tumor diagnosis?
• 1. Categorization of undifferentiated malignant tumors
◦ Use of antibodies against specific intermediate (cytoskeletal) filaments: Cytokeratins, Vimentin, Desmin etc.
• 2. Categorization of leukemias/ lymphomas 2. Determination of site of origin of metastatic tumors
• 3. Determination of molecules that have prognostic or therapeutic significance:
◦ e.g.: determination of estrogen/ progesterone receptors in
breast cancer cells -> receptor positive breast cancers have a better prognosis/ susceptible to anti-estrogen therapy (e.g. Tamoxifen -> antagonist of the estrogen receptor in breast tissue)
What is cancer cachexia? What percentage of people get it? Is it common in animals ? Why/ Why not?
- 50 % of people that develop cancer get cancer cachexia -> loss of muscle and fat.
- Not as common in animals, usually diagnosis-> death is short so its hard to see these chronic changes.
What is seen in this histologic slide of avian skin?
Thickened skin with large cells. Cells are not empty, pink things inside cells are inclusion bodies. This is typical presentation of pox virus. Not another virus will typically give you this presentation.
What is the cause of many of the familial cancer syndromes? What is the role of carcinogens? Are they common?
Many of the familial cancer syndromes are due to mutation
in recessive tumor suppressor genes
Carcinogens are cancer causing compounds
Chemical carcinogens are widespread in the environment.
E.g. The toxin of the bracken fern plant causes urinary
bladder cancer in cattle grazing pastures containing the
plant. • To b a c c o smoke contains potent carcinogens.
What is the p-53 gene? What does it do?
• p53 gene- cancer cop
◦ Growth inhibiting tumor supressor gene.
• Considered guardian of the genome.
What is occuring in this image? Is it common? Is it benign?
- Common in dogs and cats: meningiomas, benign, well confined, proliferative lesion,
- No such thing as benign tumor in brain, due to compression it will always be problematic, just depends on growth rate prognosis.
What kind of electron microscopy must be used to see avian pox?
Transmission.
What are the main mechanisms that regulate tissue growth? What cells are not very mitotic? Which are highly mitotic?
- Rate of cell proliferation (fraction of cells in the replicative pool !cells undergoing mitotic activity)
- Rate of programed cell death (apoptosis)
- hemapoeitic tissues are highly mitotic, as well as gastric mucosa, so important to remember.
- cardiac and nervous tissue dont replicate (heart and cns dont change after birth, you got what you got)
- Mutation in important gene can lead to neoplasm.
What are the effects tumors have on the host?
- Focal & hormonal effect
- Paraneoplastic syndromes
What is the condition seen in this image?
Dry Avian Pox
What is seen in this subsection of feline mammary tissue?
- section of skin in mammary area. Purple/ blue areas of hypercellularity is seen. This indicates neoplasia, since they are not clearly demarcated/ boundries are blurred it is likely malignant.
- Malignant tumor of epithelial origin -> carcinoma
What is occuring in this image? What are the yellow arrows pointing at? The black arrows?
Pink areas pushing nucleus aside are inclusion bodies, this is typical apperence of avian pox.
Yellow arrows -> individual large cells
Black arrows -> Inclusion bodies -> millions of them.
How does canine TVT evade immune destruction? What occurs with the tumor over time?
- These cells make enough MHC-I to avoid being killed by natural killer cells, (self) as well as not enough to be picked up by cytotoxic T cells/ lymphocytes (non self) and make no MHC-II to avoid detection.
Eventually lymphocytes catch up and they produce IL-6 and INF-y and then they start to produce more MHC- I and can be recognized as non self.
Tumors can regress over time, but usually they keep growing and growing, causing severe lesions.