Neoplasia I

Question 1

Ex: respiratory tract of smokers, and uterine cervix –> what is the progression of ‘plasias’

Answer 1

metaplasia –> dysplasia –> neoplasia

• once transition to neoplasia is made, process is not reversible
• dysplasia that is mild or moderate (not involvign the full thickness of the epithelium) is often reversible

Question 2

neoplasm

Answer 2

“new growth”

• abnormal mass of tissue, the growth of which exceeds, and is uncoordinated with, that of the normal tissues (= loss of responsiveness to normal growth controls)
• most neoplasms persist after cessation of the stimulus that evoked the change (how is this different from hyperplasia?)

Question 3

oncology

Answer 3

the study of neoplasms

Question 4

carcinoma in situ

Answer 4

• when dysplastic changes are marked and involve the entire thickness of the epithelium but the changes are still confined to the epithelium by the basement membrane
• considered a preinvasive neoplasm
• once the tumor cells extend beyond the basement membrane, the neoplasm is considered invasive

Question 5

When is a enoplasm considered invasive?

Answer 5

once the tumor cells extend beyond the basement membrane

Question 6

choristoma

Answer 6

tumor-like products of abnormal development

Question 7

tuberculoma

Answer 7

swelling caused by a tuberculosis infection

Question 8

Neoplasms contain what two basic tissue components?

Answer 8

• parenchyma

- reactive stroma

Question 9

Parenchyma

Answer 9

• neoplastic cells
• if closely resembles the tissue of origin, it is ‘well-differentiated’
• if does not closely resemble it at all, it is ‘poorly differentiated’

Question 10

Reactive Stroma

Answer 10

• connective tissue, blood vessels, and some variable numbers of inflammatory cells
• in some tumor types, the neoplastic cells will be derived from CT stroma, in these cases there will be some non-neoplastic stromal elements as well
• in some neoplasms, usually malignant, the parenchymal cells stimulate the production of collagenous stroma, a process known as desmoplasia

Question 11

What is desmoplasia? When does it occur?

Answer 11

• the process in which parenchymal cells stimulate the production of collagenous stroma
• usually occurs in malignant neoplasms

Question 12

Three broad categories of neoplasms are described based on the parenchymal cell type present and what germ cell layer(s) the neoplasm is derived from.
What are these categories?

Answer 12

• one parenchymal cell type (most benign and malignant neoplasms; derived from cells from a single germ cell layer)
• more than one parenchymal cell type, derived from a single germ cell layer (ex: mixed tumor of salivary gland (pleomorphic adenoma))
• more than one parenchymal cell type, derived from more than one germ cell layer (these tumors are known as teratomas; derived from cells that have the capacity to differentiate into any cell type in the body (totipotent cells); these totipotent cells are normally present in the ovary and testis)

Question 13

What are two main categories of neoplasms based on potential clinical behavior?

Answer 13

• benign

- malignant

Question 14

benign neoplasm

Answer 14

• have pathologic and clinical features which are considered indolent (remain localized, patient generally survives)
• designated by attaching the suffix -oma to the cell of origin (ex: benign tumor of fibrous tissue is called fibroma)
• an adenoma is a benign epithelial neoplasm derived from glands; a common example of a benign neoplasm of glands is a colonic adenoma , or colonic poly (polyp: structure that projects above mucosal surface); it is these polyps that are surveyed for during colonoscopy

Question 15

malignant neoplasm

Answer 15

• have potential to invade, spread, and cause death
• collectively referred to as ‘cancer’
• malignant tumors derived from mesenchymal tissue are usually called sarcomas with the specific cell of origin as the stem (ex: malignant neoplasm of fibroblasts is a fibrosarcoma)
• malignant neoplasms derived from epithelium are designated as carcinoma

Question 16

cell of origin stem:

lipo

Answer 16

adipose

Question 17

cell of origin stem:

chrondro

Answer 17

cartilage

Question 18

cell of origin stem:

fibro

Answer 18

fibroblasts

Question 19

cell of origin stem:

osteo

Answer 19

bone

Question 20

cell of origin stem:

leimyo

Answer 20

smooth muscle

Question 21

cell of origin stem:

rhabdomyo

Answer 21

striated muscle

Question 22

Tumors can be categorized based on what three features?

Answer 22

• microscopic features
• rate of growth
• local invasion and metastases

Question 23

differentiation

Answer 23

the degree to which neoplastic cells resemble the normal tissue from which they are derived, both morphologically and functionally

• benign neoplasms generally composed of well-differentiated cells
• malignant neoplasms generally composed of poorly-differentiated cells

Question 24

What is the lack of differentiation called?

Answer 24

anaplasia

Question 25

Anaplasia is characterized by what?

Answer 25

• pleomorphism (variation in size/shape of nucleus and cell)
• abnormal nuclear morphology (hyperchromatic nuclei, irregular nuclear shape, large nucleoli, and increased nucleus: cytoplasm rate (N:C) due to nuclear enlargement)
• increased mitoses with atypical features
• loss of polarity (orientation) of cells; loss of normal structure formation (e.g. glands)
• other changes: tumor giant cells, ischemic necrosis
• note: these changes may also be seen in dysplastic epithelium and benign neoplasms, but are more typical of malignant neoplasms

Question 26

Rate of growth - describe

Answer 26

• most malignant tumors grow more rapidly than do benign lesions
• hormonal stimulation and adequacy of blood supply may affect growth

*clinical correlate: the growth fraction of a malignancy may determine the response to chemotherapy since most chemotherapy agents target cells in cycle

Question 27

Local invasion and metastases - describe

Answer 27

• major cause of cancer-related morbidity and mortality

- benign neoplasms remain localized

Question 28

What are metastases?

Answer 28

secondary implants that are discontinuous with the primary tumor

Question 29

Dissemination (spreading) of tumors occurs through what three pathways?

Answer 29

• seeding of body cavities or surfaces (characteristic of carcinoma; any body cavity may be affected)
• lymphatic spread (most common pathway for initial spread of carcinomas; sarcomas may also use this route; the pattern of lymph node involvement follows the natural routes of lymphatic drainage)
• hematogenous (typical of sarcomas but also seen with carcinomas; arteries are less readily penetrated than veins)

Question 30

What is the most common cause of cancer death in both men and women?

Answer 30

lung cancer

Question 31

What is the most common cancer in men? women?

Answer 31

prostate

breast

Question 32

Geographic factors

Answer 32

thought to be more predisposing to malignancy than genetic factors

Question 33

Environmental factors

Answer 33

drugs, chemicals, radiation, viruses

Question 34

Age

Answer 34

considered biggest risk factor for cancer

• 77% of all cancers occur in persons >55 years of age
• most common cause of death in females age 40-79, males age 60-79
• why? accumulation of mutations and decline in the immune system’s surveillance for abnormal cells

Question 35

Genetic predisposition to cancer: what are the three categories?

Answer 35

less than 10% of cancer patients have an inherited mutation that puts them at risk

• inherited cancer syndromes (most autosomal dominant, increasing risk for developing neoplasm; mutation typically in tumor suppressor gene; additional mutation in second allele; ex: retinoblastoma, carriers of gene have 10000-fold increase in developing retinoblastoma)
• syndromes of defective DNA repair (inherited mutations of DNA repair lead to accumulation of additional mutations and an increased risk of malignancy; hereditary nonpolyposis colorectal carcinoma)
• familial cancers (higher frequency in certain families w/o clearly defined pattern of transmission; ex: familial carcinomas of the colon, breast, or ovary; tend to occur at an earlier age and may be bilateral)

Question 36

What are two nonhereditary predisposing ocnditions?

Answer 36

• chronic inflammation
• precancerous conditions (certain non-neoplastic disorders (such as solar keratosis of skin, ulcerative colitis, etc) have such a well-defined association with cancer that they have been termed precancerous conditions)