Neoplasia I Flashcards
1
Q
Ex: respiratory tract of smokers, and uterine cervix –> what is the progression of ‘plasias’
A
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
2
Q
neoplasm
A
“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?)
3
Q
oncology
A
the study of neoplasms
4
Q
carcinoma in situ
A
- 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
5
Q
When is a enoplasm considered invasive?
A
once the tumor cells extend beyond the basement membrane
6
Q
choristoma
A
tumor-like products of abnormal development
7
Q
tuberculoma
A
swelling caused by a tuberculosis infection
8
Q
Neoplasms contain what two basic tissue components?
A
- parenchyma
- reactive stroma
9
Q
Parenchyma
A
- 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’
10
Q
Reactive Stroma
A
- 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
11
Q
What is desmoplasia? When does it occur?
A
- the process in which parenchymal cells stimulate the production of collagenous stroma
- usually occurs in malignant neoplasms
12
Q
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?
A
- 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)
13
Q
What are two main categories of neoplasms based on potential clinical behavior?
A
- benign
- malignant
14
Q
benign neoplasm
A
- 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
15
Q
malignant neoplasm
A
- 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
16
Q
cell of origin stem:
lipo
A
adipose
17
Q
cell of origin stem:
chrondro
A
cartilage
18
Q
cell of origin stem:
fibro
A
fibroblasts
19
Q
cell of origin stem:
osteo
A
bone
20
Q
cell of origin stem:
leimyo
A
smooth muscle
21
Q
cell of origin stem:
rhabdomyo
A
striated muscle
22
Q
Tumors can be categorized based on what three features?
A
- microscopic features
- rate of growth
- local invasion and metastases
23
Q
differentiation
A
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
24
Q
What is the lack of differentiation called?
A
anaplasia
25
Anaplasia is characterized by what?
- 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
26
Rate of growth - describe
- 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
27
Local invasion and metastases - describe
- major cause of cancer-related morbidity and mortality
| - benign neoplasms remain localized
28
What are metastases?
secondary implants that are discontinuous with the primary tumor
29
Dissemination (spreading) of tumors occurs through what three pathways?
- 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)
30
What is the most common cause of cancer death in both men and women?
lung cancer
31
What is the most common cancer in men? women?
prostate
| breast
32
Geographic factors
thought to be more predisposing to malignancy than genetic factors
33
Environmental factors
drugs, chemicals, radiation, viruses
34
Age
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
35
Genetic predisposition to cancer: what are the three categories?
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)
36
What are two nonhereditary predisposing ocnditions?
- 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)
