5.10 - Intro to Pathology Pt 1: Neoplasia

Question 1

Define Neoplasia

Answer 1

Means new growth and is used to denote uncontrolled growth of cells whose proliferation cannot be adequately controlled by normal regulatory mechanisms operating in normal tissues.

Question 2

Define Tumor

Answer 2

The terms neoplasia and tumor are used synonymously, but realize that not all form tumors ( i.e. Leukemias), and not all swellings are neoplasms (inflammations).

Question 3

Define Oncology

Answer 3

The greek word for swelling “Onkos” which has been used to construct the term Oncology, the scientific word for the study of cancer.

Question 4

Who determines the definitive diagnosis?

Answer 4

The definitive diagnosis of tumors, whether benign or malignant is achieved by the pathologic examination.

Question 5

General Characteristics of Benign tumors

Answer 5

Have a limited growth potential and good outcome

Question 6

Benign tumors Macroscopical

Answer 6

Are sharply demarcated from normal tissue and are often encapsulated. The capsule is usually composed of connective tissue. Benign tumors have an expansile growth and usually compress the normal surrounding tissue.

Question 7

Benign tumors Microscopical

Answer 7

• Benign tumors are composed of cells that resemble the tissue from which they have arisen.
• The cells are composed of uniform population in which all the cells have the same features, with the regularly shaped round or oval nuclei but all the same size with evenly distributed chromatin with normal nucleoli.
• They also have a well developed cytoplasm.

Question 8

Malignant tumors general characteristics

Answer 8

Grow uncontrollably and may eventually kill the host

Question 9

Macroscopically malignant tumors

Answer 9

• They invade the surrounding tissue by infiltration, causing a hallmark “hemorrhage and Necrosis” within the tissue.
• Malignant tumors lack a capsule and are not sharply demarcated from normal tissue.
• Because of their infiltrative growth and lack of sharp borders, malignant tumors cannot be removed as easily as benign ones.

Question 10

Microscopically Malignant tumors

Answer 10

• Malignant cells show prominent Anaplasia (disorganized growth) in that they exhibit new features not inherent to the tissues of their origins.
• Undifferentiated (very immature cells)
• Heterogeneous population of cells that often show mocked pleomorphism or variability (different sizes and shapes)
• The have uneven hyper chromatic nuclei that vary in shape and size. The nuclei are normally larger, mor prominent and may have multiple nucleoli. They are rapidly proliferating and have no specialized cytoplasmic function and therefore exhibit very little cytoplasm.

Question 11

What is a high nuclear/cytoplasmic ration? (High N/C Ratio)

Answer 11

Because malignant tumors exhibit a large nucleus surrounded by a thin rim of cytoplasm, the ratio is 1:1 instead of the normal 1:5 ratio.

Question 12

Define Pleomorphism

Answer 12

Variability in the size and shape of cells and or their nuclei

Question 13

Define Undifferentiation

Answer 13

A cancer in which the cells are very immature and primitive and do not look like cells in the tissue from which it arose. As a rule an undifferentiated cancer is more malignant that a cancer of that type which is well differentiated. Undifferentiated cells are said to be anapestic.

Question 14

Define Metastasis

Answer 14

A process by which cells move from one site to another in the body. It involves a spread of malignant tumor cells from a primary location to some other sire in the body. Only malignant tumor cells have this capacity. Benign tumors are always localized.

Question 15

Are all malignant cells capable of metastasis?

Answer 15

No, some such as primary brain tumors cannot leave the area they started.

Question 16

What are the three main pathways malignant cells spread in the body?

Answer 16

1) Lymphatics
2) The bloodstream
3) Direct extension of the primary tumor, usually by seeding of the surface of body cavities (Renal cell carcinoma seeding to the adrenal gland)

Question 17

Explain Benign Taxonomy

Answer 17

The cells of benign tumors usually retain the microscopic features of their tissue of origin. The tumors are thus named according to the cell type which they resemble the most, with the addition of the suffix “oma”. Thus if epithelial and of glandular origin, the tumor is an Adenoma( colon tubular adenoma), if squamous the benign tumor is a papilloma (skin or laryngeal papillomas)

Question 18

Benign Connective tissue tumors

Answer 18

If the benign tumor is of connective tissue origin, the same rules apply with “oma” being attached to the tissue of origin:

1) Cartiage tissue is a Chondroma
2) Osseous tissue is a Osteoma
3) Smooth muscle is a Leiomyoma
4) Fat tissue is a Lipoma

Question 19

Explain Malignant tumor Taxonomy

Answer 19

• The malignant tumors of epithelial origin are called carcinomas
• (Squamous cell carcinoma, adenocarcinoma, traditional cell carcinoma, or mesothelioma, due to long term asbestos exposure)
• Tumors composed of unique cell types are named accordingly such as renal cell carcinomas, adrenocortical carcinomas, or hepatocellular carcinomas.

Question 20

Explain Malignant connective tissue tumors

Answer 20

The name for the malignant tumors of connective tissue origin are coined from the root of the cell type and suffix “Sarcoma”

1) Fibrous tissue Fibrosarcoma
2) Fat tissue Liposarcoma
3) Bone tissue Osteosarcoma
4) Skeletal muscle is Phabdinyosarcoma

Question 21

What suffix is applied to Benign tumors mostly

Answer 21

“oma”

Question 22

What suffix is applied to Malignant connective tissue tumors?

Answer 22

“Sarcoma”

Question 23

Define Tumor Grading

Answer 23

• Histologic grading is based on the degree of anaplasia and on the number of proliferating cells.
• Anaplasia is determined by the shape and irregularity of the cells large number of atypical mitoses, nuclear pleomorphism and tumor giant cells.
• Grading of cancer is done by the pathologist.

Question 24

Define Tumor Staging

Answer 24

Describes the severity of an individual’s cancer based on the magnitude of the original (primary) tumor as well as on the extent cancer has spread in the body.

Question 25

What is a Grade 1 tumors?

Answer 25

Well-differentiated tumor

Question 26

What is a Grade 2 Tumor?

Answer 26

Moderately Differentiated tumor

Question 27

What is a Grade 3 tumor?

Answer 27

Poorly or Undifferentiated Tumor

Question 28

What factors contribute to the clinical staging of a tumor by the Oncologist?

Answer 28

1) The choice of medical versus surgical treatment approach to cancer us influenced by the stage of a tumor, which refers to the extent of spread.
2) The staging is done by clinically assessing the extent of tumor spread based on physical examination, radiographic studies, and biopsy results and takes into account the size and grading of the primary tumor and the presence or absence of lymph node and distant metastasis.
3) The TNM cancer staging system gives a number designation to tumor size, lymph node status and Metastasis to determine the stage.

Question 29

Are there exceptions to the naming rules?

Answer 29

Yes not all tumors that end in “oma” are benign, the most important examples of this inconsistent nomenclature includes: Lymphomas, Melanomas, Astrocytomas, and Seminomas which are all malignant. Also, Malignant pediatric tumors composed of embryonic tissue are called “Blastomas”

Question 30

Interpret the finding of the TNM staging System for tumors and relate it to the prognosis.

Answer 30

There are marked orations of this system depending upon which primary organ involved, and commonly used criteria in most includes tumor size, extent of local spread within the organ, lymph node metastasis and distant metastasis. Clearly the presence of lymph node metastasis mandates more aggressive treatment than does their absence, whereas the presence of distant metastasis is generally a contraindication to surgical intervention other than palliation.

Question 31

What are Teratomas?

Answer 31

• Tumors derived from all three germ cell layers, usually in the testes or ovaries.
• Are named Teratomas (benign) or Teratocarcinomas (malignant). They may also be seen in the midline of the body (mediastinum or sacrococcygeal region.

Question 32

What are some tumors named after their discoverer?

Answer 32

Hodgkin’s lymphoma, Ewing’s Sarcoma of bone, and Kaposi’s Sarcoma of the skin.