Special pathology - oncology

Question 1

oncology defintion

Answer 1

the study of neoplasms

Question 2

neoplasia definition

Answer 2

the process by which normal cells undergo irreversible genetic changes that render them unresponsive to ordinary controls of growth

Question 3

neoplasm definition

Answer 3

grossly or microscopically detectable mass composed of benign or malignant neoplastic cells

(also termed tumor or cancer)
(the term cancer is applied only to malignant neoplasms)

Question 4

All tumors have what two basic components:

Answer 4

neoplastic cells that constitute the tumor parenchyma

reactive stroma made up of connective tissue, blood vessels, and variable numbers
of cells of the adaptive and innate immune system

Question 5

classification of tumors and their biological behavior is based on

Answer 5

parenchymal component

Question 6

Anaplasia

Answer 6

lack of differentiation

Benign tumors are well differentiated
Malignant tumors are poorly differentiated

Question 7

Pleomorphism

Answer 7

variation in shape and size

Question 8

morphological features of a malignant neoplasm (7)

Answer 8

Malignant tumors are poorly differentiated
Anaplasia – lack of differentiation
Pleomorphism – variation in shape and size

Abnormal nuclear morphology – disproportionately large nuclei
Mitoses (replicating cells)
Capsule often absent or incomplete
Other changes – necrosis, angiogenesis

Question 9

Cancer definition

Answer 9

a disease in which some of the body’s cells proliferate uncontrollably and spread to other parts of the body

Question 10

Tumor or neoplasia? explain

Answer 10

two terms used in oncology

Many medical professionals suggest that both these terms refer to the same type of abnormal cellular growth which can either be benign or malignant. Thus these terms are often used interchangeably.

However some experts suggest that there is a difference between tumor and neoplasm; according to some - a tumor is a swelling or lump without any inflammation.
A neoplasm refers to new growth, lesion or ulcer.

Question 11

proto-oncogenes

Answer 11

A gene involved in normal cell growth.

Mutations (changes) in a proto-oncogene may cause it to become an oncogene,
which can cause the growth of cancer cells.

Oncogenes accelerate cell proliferation. Mutuation is a key feature of oncogene activity.

Question 12

tumor suppressor gene

Answer 12

A type of gene that makes a protein called a tumor suppressor protein that helps control
cell growth.

Mutations (changes in DNA) in tumor suppressor genes may lead to cancer. Also called antioncogene.

Question 13

tumor virus

Answer 13

Viruses that are shed from tumors that infect normal growing cells by inserting the viral RNA or DNA into the normal cell may transform the normal cells into tumor cells.

An Oncogenic virus is a virus that causes cancer

Question 14

Carcinogenesis

Answer 14

Process by which tumors develop as the result of successive genetic and epigenetic changes.

also termed neoplastic transformation

sometimes used synonymously with stepwise tumor development or multistage carcinogenesis

Begins with the development of genotoxic (DNA toxic) changes within a normal cell.
The cell can no longer control its own growth or location.

Question 15

Phases of tumor development

Answer 15

1. Initiation - An irreversible alteration of genetic material
2. Promotion - The selective outgrowth of initiated cells to form a benign tumor
3. Progression - The gradual development of features of malignancy due to a combination of genetic and epigenetic changes

Question 16

first phase of tumor development involves?

Answer 16

1. Initiation - An irreversible alteration of genetic material

Question 17

second phase of tumor development involves?

Answer 17

2. Promotion - The selective outgrowth of initiated cells (genetically altered) to form a benign tumor

Question 18

third phase of tumor development involves?

Answer 18

3. Progression - The gradual development of features of malignancy due to a combination of genetic and epigenetic changes.

Question 19

what are epigenetic changes?

Answer 19

Epigenetics is the study of how your behaviors and environment can cause changes that affect the way your genes work. Unlike genetic changes, epigenetic changes are reversible and do not change your DNA sequence, but they can change how your body reads a DNA sequence.

Question 20

name 5 Cancer cell characteristics

Answer 20

Local increase in cell numbers
Loss of normal arrangement of cells
Cell shape and size vary from normal

Division in an uncoordinated manner
Destruction of neighboring tisuse

Question 21

explain Tumor spread and give 3 mechanisms

Answer 21

Extension of the primary tumor into surrounding areas

Metastasis via lymph and veins
Angiogenesis
Distribution of metastasis

Question 22

Metastasis

Answer 22

Migration of cancer cells from the primary site or tumor where they originate to a distant site and the invasion to other tissues.

Question 23

Microscopically, most tumors consist of

Answer 23

a single cell type, either mesenchymal or epithelial, and the name of the neoplasm reflects the cell type from which the tumor is thought to arise.

named for the organs or tissues where they form
may be described by the type of cell that formed them

Question 24

Mesenchymal tumors arise from?
Epithelial tumors arise from?

Answer 24

connective tissue (sarcoma)
epithelial tissue (carcinoma)

Question 25

Round cell tumors refer to?

Answer 25

melanoma, mast cell tumor etc.

Question 26

Carcinoma is the most what

Answer 26

most common type of cancer.

formed by epithelial cells (cells that cover the inside and outside surfaces of the body)

Carcinomas that begin in different epithelial cell types have specific names.

Question 27

Adenocarcinoma is a cancer that forms in

Answer 27

epithelial cells that produce fluids or mucus (glandular tisuse).

Question 28

Squamous cell carcinoma is a cancer that forms in

Answer 28

squamous cells

(are thin, flat cells that look like fish scales, and are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the lining of the respiratory and digestive tracts.)

Question 29

Transitional cell carcinoma is a cancer that forms in

Answer 29

a type of epithelial tissue called transitional epithelium, or urothelium.
so the urinary bladder

Question 30

Sarcomas are

Answer 30

cancers that form in bone and soft tissues including muscle, fat, blood vessels, lymph vessels, and fibrous tissue (such as tendons and ligaments)

osteosarcoma is the most common cancer of bone.
soft tissue sarcomas such as leiomyosarcoma, liposarcoma

Question 31

Leukemias are

Answer 31

Cancers that begin in the blood-forming tissue of the bone marrow.

Leukemia is a great over-abundance of a particular white blood cell in the
bloodstream. hese cancers do not form solid tumors.

They involve large numbers of abnormal white blood cells (leukemia cells and leukemic
blast cells) build up in the blood and bone marrow, crowding out normal blood cells.

The low level of normal blood cells can make it harder for the body to get oxygen to its tissues, control bleeding, or fight infections.

Question 32

Melanoma is a cancer that begins in

Answer 32

cells that become melanocytes, which are specialized cells that make melanin.

Most melanomas form on the skin, but melanomas can also form in other pigmented tissues, such as the eye.

Question 33

Sarcoid Tumours are

Answer 33

The most common equine tumor (approx. 40 % of all equine cancers).
Can occur in any breed and at any age.
Can be found anywhere on the body (often on the head, near the genitals, and on the underside of the abdomen).

May also form at sites of previous injury or scarring. Although non-malignant - can spread aggressively, occurring as single or multiple lesions ranging from small and wart-like to large, ulcerated, fibrous growths that can impacts quality of life.

Bovine papillomavirus is believed to be involved in the development of sarcoid tumours, although its precise role is not known.

Question 34

Basal cell tumors are

Answer 34

cancers that start in the basal cell layer, which is the lower part of the epidermis.

These cancers usually develop on sun-exposed areas, especially the face, head, and neck. They tend to grow slowly.

Question 35

Squamous Cell Carcinoma is

Answer 35

the most common malignant skin tumour in horses

typically affecting nonpigmented, poorly-haired areas near mucous membranes such as around the eyes, lips, nose, anus, and external genitalia

appearing as raised, irregular masses, this is an invasive, often slow-growing cancer that can later spread internally

most commonly diagnosed in horses 12 years of age and older

Question 36

Melanoma is

Answer 36

a tumour of dark-pigmented skin, most melanomas in horses are found in those with gray coats where the hair turns gray or white with age.
approximately 80 percent of grey horses over 15 years of age will have melanomas.

typically appear as rounded black nodules of varying size under the dock of the tail, in genital areas, and on the head around the mouth and eyelids.

Question 37

Paraneoplastic syndrome comprises

Answer 37

systemic clinical signs caused by release of tumor cell products.

They are an extremely diverse group of clinical aberrations that are associated with the non-invasive actions of the tumor.

Cachexia
Alopecia
Erythrocytosis
Fever
Glomerulonephritis
Hypoglycemia
Anemia
Thrombocytopenia
etc.

Question 38

RT is

Answer 38

an abbreviation for radiation therapy (also called radiotherapy) which is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumours.

Question 39

Radiotherapy is

Answer 39

another term for radiation therapy (RT), a treatment for cancer.

Question 40

A cancer’s grade describes

Answer 40

how abnormal the cancer cells and tissue look under a microscope when compared to healthy cells.

Question 41

Radionuclide therapy uses

Answer 41

radioactive substances called radiopharmaceuticals to treat medical conditions, particularly cancer.

Question 42

Neoadjuvant is

Answer 42

treatment given as a first step to shrink a tumour before the main treatment, which is usually surgery, is given. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy. It is a type of induction therapy.

Question 43

Round cell tumour typically refers to

Answer 43

melanomas, mast cell tumours etc. Round cell tumours, as the name suggests, are comprised of round cells with increased nuclear-cytoplasmic ratio.

Question 44

The stage of a cancer describes

Answer 44

the size of a tumour and how far it has spread from where it originated.

Question 45

in what type of tissue is a sarcoma found

Answer 45

mesenchymal so connective tissue

Question 46

in what type of tissue is a carcinoma found

Answer 46

parenchymal and epithelial tissues