Pathology and Disease Exam 5/6

What is Neoplasia?

\-process of new growth

\-normal cells undergo irreversible genetic changes and makes them unresponsive to ordinary controls on growth

\-due to the transformed cell within

What are the other two common terms for neoplasms?

\-tumor (“swelling”)

\-Cancer (“crab”)

What is oncology?

\-the study of neoplasia

What does the word oncos mean?

\-tumor

What does “cancer” denote?

\-a malignant growth

True or False: “Tumor” or “mass” may be neoplasm or a nonneoplastic lesion like a granuloma

TRUE!

What does neoplasm mean?

\-cancerous

What does nonneoplastic lesion mean?

\-non-malignant

\-benign

Meaning of Benign

\-harmless

\-do not invade surrounding tissue

\-do not spread to new anatomic locations within the body

\-curable and are rarely responsible for death of an animal

Meaning of Malignant

\-harmful

\-invade locally

\-spread by metastasis (change of place)

\-kill animal by interfering with critical body functions

What is the exception for benign nervous system tumors?

\-even though it is benign, can cause death due to it being in the nervous system

Cells go from Normal to Preneoplastic to Neoplastic, what are the 4 preneoplastic changes to cells

\-Hypertrophy

\-Hyperplasia

\-Metaplasia

\-Dysplasia

Mesenchymal Tumors

\-arise from embryonic mesodermal origin

\-composed of spindle cells arranged in streams and bundles

\-bengin tumors use suffix -oma

\-malignant tumors use sarcoma

Define Fibrosarcoma

\-malignant tumor (mesenchymal tumor) composed of fibroblasts

True or False: The cells of the Hematopoietic system are also mesenchymal?

True

Are lymphoma and lymphosarcoma the same thing?

yes, they are both malignant in this case

Suffix Oma meaning

\-benign tumors

suffix sarcoma meaning

\-malignant tumors

Malignant form of tumor that arises from Chondrocytes

\-Chondrosarcoma

Malignant form of tumor that arises from Osteocytes

Osteosarcoma

Benign form of tumor that arises from Chondrocytes

\-Chondroma

Benign form of tumor that arises from Osteocytes

\-osteoblastoma

What is the difference between Oma and carcinoma?

\-oma is from mesenchymal origin (benign)

\-carcinoma (cancers)is all malignant tumors of epithelial origin

What is the difference between adenoma and adenocarcinoma?

\-ademona is a benign tumor arising from glandular epithelium (ex. mammary epithelium)

\-adenocarcinoma is a malignant tumor having a glandular growth pattern (epithelium)

Epithelioma

\-benign tumor of epithelial cells

Fibroma

\-benign tumor of fibrocytes

Chondroma

\-benign tumor of chondrocytes

Adrenocarcinomas

\-malignant tumor derived from glandular epithelium

Squamous cell carcinomas

\-malignant tumor of squamous cell from epithelial

What is a mixed tumor?

\-a tumor containing multiple cell types

\-arise from a single pluripotent or totipotent stem cell capable of differentiating into a variety of more mature cell types

What is a teratoma?

\-arise from totipotential germ cells

\-contain tissues normally derived from all three embryonic cell layers

\-may be composed of a bizarre mixture of adult and embryonic tissue types

\-benign

What is a hamartoma?

\-disorganized but mature mesenchymal or epithelial tissues found in their normal anatomic location

\-consist of abnormal proliferations of blood vessels

What is choristomas

\-composed of normal mature tissue located at an ectopic site (out of place)

What is a dermoid?

\-a mass consisting of mature skin and adnexa

\-may be found in a variety of unusually site, including the cornea

Characteristics that make up a tumor

\-may arise from virtually any normal tissue in the body

\-benign tumors are expansile masses and may compress but do not invade surrounding tissue and do not spread to other sites in the body

\-malignant tumors are locally invasive and have the potential to metastasize to distant sites

3 tumor characteristics

\-loss of differentiation

\-unlimited proliferative potential

\-tumor grade and stage (extent of spread)

Differences between Benign and Malignant

\-benign=generally expansile and may compress adjacent tissue

\-malignant= usually invasive, alterations to cell adhesion, motility, and protease production allow tumor cells to leave the tumor and penetrate surrounding tissue, become completely independent of local growth regulatory controls and acquire an independent blood supply

Anaplasia

\-poor differentiation

\-loss of differentiation of cells and of their orientation to one another

Anisocytosis

\-wide variation in cell size

Pleomorphism

\-wide variation is cell shape and size

Anisokaryosis

\-extreme variability in nuclear size

Differentiation Therapy

\-tumor cells can be forced to differentiate into more mature, near-normal cells

Steps a cell goes through from normal to abnormal (3 steps)

\-Initiation

\-Promotion

\-Progression

Initiation Step

\-an irreversible alteration of genetic material 

Promotion Step

\-the selective outgrowth of initiated cells to form a benign tumor

Progression Step

\-the gradual development of features of malignancy due to a combination of genetic and epigenetic changes

Define three major ways the tumor interacts with tissue?

\-Tumor-stromal interactions

\-Tumor Immunity

\-Paraneoplastic effects

Tumor-stromal interactions

\-tumor cells and their stroma exert considerable mutual control by interacting via signaling molecules

\-growth factors, cytokines, hormones, and inflammatory mediators

\-modulate the growth rate, differentiation state, and behavior if both stroll and tumor cells

Tumor Immunity

\-the immune system may recognize tumor antigens as foreign and destroy tumor cells

\-Innate immune system and the adaptive immune system

\-Tumor cells may employ a number of strategies to evade immunosurveillance

Innate immune system

\-natural killer cells, macrophages

Adaptive immune system

\-cytotoxic T lymphocytes, B lymphocytes

Paraneoplastic effects

\-Tumors cause clinical disease through direct means, such as compression or effacement of normal tissues

\-OR Paraneoplastic effects, such as the secretion of hormones by the tumor

Parenchyma

\-a tumor consists of the tumor cells proper

Stroma

\-nonneoplastic supporting structure

\-composed of extracellular connective tissue, proteins, glycoproteins (collagen)

What is an interstitial cell tumor? 

\-lies within the testis and is surrounded by a thick connective tissue capsule

\-fibrous capsules are common surrounding benign tumors than surrounding malignant tumors

Describe the development and composition of a squamous cell carcinoma.

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\-**Carcinomas and adenocarcinomas that stimulate the formation of abundant collagen in surrounding connective tissue (desmoplasia) may be termed “scirrhous.”** 

\-**Tumor-associated fibroblasts may secrete a fetal type of extracellular matrix and coevolve with adjacent tumor cells.**

What is angiogenesis?

\-Tumors depend absolutely on an adequate blood supply to provide oxygen and nutrients to tumor cells. 

\-Without the development of new blood vessels tumors are limited to a maximum diameter of 1 to 2 mm. 

What is Lymphangiogenesis? 

\-The development of lymphatic vasculature in tumors, termed, shares many features with tumor angiogenesis. 

\-Tumor-associated lymphatic vessels sprout from preexisting lymphatic vessels in response to tumor-secreted factors such as VEGF.

\-Tumor-associated lymphatic vessels are essential for metastasis of solid tumors to regional lymph nodes. 

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How does inflammation occur within a tumor? 

\-**I**nflammatory cells are attracted to tumors by chemokines and cytokines released by tumor cells. 

\-In general, inflammation does not appear to protect against tumors. 

\-In fact, many chronic inflammatory conditions increase the risk for cancer in affected organs. 

Vaccine-associated sarcomas in cats is clearly linked to the presence of …

\-inflammation at sites of inoculation

What is immunosurveillance? 

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What is a tumor specific shared antigen? 

What are differentiation antigens?

What is an antitumor effect mechanism?

What are the four steps in Evasion to Immune Responses 

What is Tumor immunotherapy?

How do tumors disseminate?  What are the steps of tumor dissemination? 

What is Metastasis suppression?

What is a Transmissible tumor? \n \n