Neoplasia Flashcards
Condition

Mammary tumor
Mesenchymal Tumors
Arise from cells of mesodermal origin
_______________________
Benign = -oma
Malignant = -sarcoma
Experimentally Induced (Nude Mice)
Able to accept grafting: no rejection
Example of what characteristic of malignant tumors

Metastasis
Hypercalcemia of malignancy
Due to the production of calcemic humoral substances by neoplastic cells from extra osseous neoplasms
Is this an example of a benign or malignant tumor?

Benign
(Macro/Micro) Environmental Cause

Macro- Environmental cause
Examples of paraneoplastic syndromes
Cachexia
Hypercalcemia
Hypoglycemia
Thrombotic disease
Peripheral neuropathy
Nodular dermatofibrosis
Hypertrophic osteroarthropathy
Differentiation / Anaplasia
The extent to which parenchymal cells resemble the correspondent normal parenchymal cells
Paraneoplastic syndrome

Cancer cachexia
TNM System
System of staging
Classification of tumor

Mixed Tumor
Major immune defence mechanism against tumors
CD8+ Cytotoxic T Lymphocytes (CTLs)
Benign Epithelial Tumors
Papilloma → exophytic growth from and epithelial surface → benign epithelial tumor that projects from a mucosal surface
(Malignant/Benign) tumors are infiltrative and invade and destroy the surrounding tissues
Malignant
Neoplasia
Process of tumor formation
(Macro/Micro) Environmental Cause

Micro-Environmental
Example of benign or malignant tumor

Benign
_________________________
Will cause clinical signs depending on location!!!
Stroma
Connective tissue and blood vessels that support the neoplastic cells
Halmark of malignancy
Metastasis
Condition

Pituitary Adenoma
Cancer Cachexia
Progressive loss of body fat and lean body mass, accompanied by profound weakness, anorexia and anemia
Benign tumors are (un/well) differentiated
Well Differentiated
T/F: In general, the growth rate of tumors correlates with their level of differentiation.
True
__________________
Most malignant tumors grow more rapidly than do benign lesions
Condition

Meningioma
Metastases
Tumor implants discontinuous with the primary tumor
Characteristics of successful subclones
High proliferative rate
Evades the host immune response
Can stimulate developement of independent blood supply
Independent of exogenous growth factors
Can spread to distant sites
Tumor Associated Antigens
Expressed on neoplastic cells, but may be expressed on normal cells also
Paraneoplastic syndromes
Indirect and usually remote effects caused by tumor cell products rather than the primary tumor and its metastases
Condition

Nasal Squamous Cell Carcinoma
T/F: Anaplasia represent reverse differentiation of normal cells
False
They arise from less differentiated stem cell - like cells
Teratomas
Arise from totipotent germ cells. Contain all embryonic cell layers and consist of a bizarre mixture of adult and embryonic tissue types
Malignant Epithelial Tumors
Carcinoma
___________________
Carcinoma in situ
Malignant neoplasms are (un/well) differentiated
Can be well differentiated or undifferentiated
Oncology
Study of tumors or neoplasms
Neoplasm
“New Growth” - composed of cells originally derived from normal tissues that ahve undergone heritable genetic changes that allows them to become relatively unresponsive to normal growth controls and expand beyond their normal anatomic boundary
Condition

Hypertrophic Osteopathy
__________________________________
Marie’s Disease
(Macro/Micro) Environmental Cause

Macro-Environmental
Neoplasms present alteration is what that allows genomically instable cells to replicate
Apoptotic Pathway
What should you take into account when differentiating between benign and malignant tumors?
Differentiation / anaplasia
Rate of growth
Local invasion
Presence of absence of metastasis
Changes in cell physiology that together determine malignant phenotypes
Self sufficiency in growth signals
Insensitvity to growth inhibitory signals
Evasion of apoptosis
Defects in DNA repair
Limitless replicative potential
Sustained angiogenesis
Ability to invade and metastasize
Abilty to escape immunity and rejection
Main mechanisms that regulate tissue growth
Rate of cell proliferation
Rate of programmed cell death
Etiologies of tumors
Maco-environmental (extrinsic) causes
Micro-environmental (intrinsic) causes
Condition

Nephroblastoma
M in TNM system
Blood-borne metastases
M0 = no blood borne metastases
M1 or M2 indicates the presence of blood borne metastases and some judgement as to their number
Clinical signs of hypercalcemia
Muscle weakness
Cardiac arrhythmia
Anorexia
Vomiting
Renal Failure
Polyruia/Polydipsia
Mixed Tumors
Multiple cell types derived from a single or multiple germ cell layers - pluripotential or totipotential cell
Four classes of normal regulatory genes are the main target of genetic damage and play a significant role in carcinogenesis
Growth promoting proto-oncogenes
Growth inhibiting tumor suppressor genes
Genes that regulate programmed cell death (apoptosis)
Genes involved in DNA repair
Metaplasia
Reversible change in which one adult cell type is replaced by another adult cell type of the same germ cell line
90% of mammary tumors in cats are (benign/malignant)
Malignant
Effects of tumors on the host
Local and hormonal effect
Paraneoplastic syndromes
___________ interactions play an important role in carcinogenesis.
Tumor-Stromal interactions play an important role in carcinogenesis.
Condition

Squamous Cell Carcinoma
Why are paraneoplastic syndromes important?
May represent the earliest manifestation of an occult neoplasm
Affected patients may represent significant clinical problems and may even be lethal
Anaplasia is characterized by
Pleomorphism
Abnormal nuclear morphology
High mitotic rate
Loss of polarity - disorganization
Types of tumor antigens
Tumor specific
Tumor associated
Example of benign or malignant tumor?

Malignant
Condition

Squamous cell carcinoma
Condition

Nodular Dermatofibrosis
Most common epigenetic changes
DNA methylation
Histone modification
Classification of tumor

Mixed Tumor
_____________________
Teratoma
p53 Gene
Growth inhibiting turmor suppressor gene - guards the genome
Two basic components of a neoplasm
Parenchyma
Stroma
N in the TNM system
Regional lymph node involvement
N0 = No LN involvement
N1 to N3 would denote increase number and range of nodes
Why are immune surveillance mechanisms not as effective as they should be?
Tumor cells have the capability to develop mechanisms to evade the immune system of the immunocompetent host
Desmoplasia
Formation and development of collagen-rich fibrous connective tissue stroma
Epigenetic Changes
Heritable changes in gene expression in somatic cells resulting from something other than a change in the DNA sequence
Paraneoplastic syndrome

Hypercalcemia
Genetic alterations that contribute to cancer development include
Inheritable changes
Somatic changes
Condition

Thyroid adenoma
Tumors are classified as
Mesenchymal tumors
Epithelial tumors
Undifferentiated tumors
Mixed tumors
Most frequently observed paraneoplastic syndrome in dogs?
Hypercalcemia
Pathways of spread of malignant tumors
Transcoelomic spread
Lymphatic spread
Heatogenous spread
Staging of Tumors
Based on the size of the primary tumor, its extent of spread to regional lymph nodes and the presence or absence of hematogenous metastases
Cells involved in immune-surveillance against tumors
CTL
NK
B Lymphocyte
Macrophage
Grading Tumors
Semi-quantitative evaluation of the degree of differentiation of the tumor. Cancers are classified from I to IV with increasing anaplasia
Example of what pre-neoplastic change

Metaplasia
From a clinical point of view is staging or grading more useful
Staging
DDX of hypercalcemia
Hyperparathyroidism
Renal Failure
Hypoadrenocorticism
Hypervitaminosis D
Tumor heterogeneity occurs due to
Tumor growth - progressive accumulation of heritable changes in tumor cells
Example of a benign or malignant tumor?

Benign
T in the TNM System
Primary tumor, with increasing size T1 to T4
T0 = in situ lesion
Advantages to use of immunohistochemistry in tumor diagnosis
Categorization of undifferentiated malignant tumors
Categorization of leukemias/lymphomas
Determination of site of origin of metastatic tumors
Determination of moleculesthat ahve prognostic or therapeutic significance
Immunohistochemistry
Availability of monoclonal antibodies has greatly facilitated the identification of cell products or surface markers
Metaplasia is usually and adaptive response to
Chronic irritation
Phenotypes of Cancer
DNA mutations
Epigenetic changes
Chromosomal alterations
Epithelial metaplasia is commonly to what type of epithelium
Squamous epithelium
Metastatic Cascade
- Loss of cadherin and catenin function
- Integrin and other receptors bind to ECM components
- Degradation of BM and ECM components occurs by increased protease activity
- Migration - cytoskeleton alterations together with alteration in ECM adhesion structures - stimulated by autocrine growth factors
Epithelial Tumors
Primarily arise from cells of endodermal and ectodermal origin
What lies at the heart of carcinogenesis
Non-lethal genetic damage
Pre-neoplastic changes that can lead to neoplastic cells
Metaplasia
Dysplasia
T/F: Histologic appearance always correlates with biologic behavior
False