Unit 4.5 and 4.6 Flashcards
New Growth - “an abnormal mass of tissue, with excessive and uncoordinated growth that persists after the original stimulus is absent”
neoplasia
originally used to describe inflammation, now the term implies “neoplasia”
tumor
doesn’t invade local tissues but may still cause disease
benign
invades and spreads within the body (metastasis), resulting in death
malignant
What type of progression in neoplasia?
stepwise
a disorderly pattern of growth (ill defined term)
dysplasia
loss of differentiation:
anaplasia
For tumors there is/are usually ___ cell(s) of origin. What are the two categories of cells they can be?
1; mesenchymal or epithelial
For a mesenchymal tumor, we use the suffix _____ for benign tumors, and __________ for malignant tumors.
-oma; -sarcoma
tumors that can arise from endoderm, mesoderm, or ectoderm:
epithelial
benign epithelial tumor, from a gland, or making a tubular pattern:
adenoma
benign epithelial tumor that is exyophytic/frondose (sticking out from a surface) from a skin or mucosal surface
papilloma
benign epithelial tumor that is smooth and bulging from the mucosal surface
polyp
Adenocarcinoma has a:
glandular pattern
malignant epithelial tumors have the suffix:
-carcinoma
preinvasive form, neoplasm remains within the epithelium without invasion
carcinoma in-situ
tumors that demonstrate stratified squamous epithelium
squamous cell carcinoma
tumors that produce abundant mucin
mucinous carcinoma
formation of abundant collage stroma (scirrhous response) around areas of tumors:
desmoplasia (a type a carcinoma)
Indicates that the tumor is particularly invasive:
desmoplasia
mixed tumors =
multiple cell types
stem cell origin tumors -
differentiates into various mature cell types
disorganized mature cells in a normal location
hamartoma
normal mature tissue in an abnormal site (dermoid)
choristoma
What are the differentiation characteristics of benign tumors? (3)
- well differentiated
- structure similar to tissue of origin
- no anaplasia
What are the differentiation characteristics of malignant tumors (3)?
- poorly differentiated
- tissue of origin may be unclear
- variable anaplasia
What are the growth rate characteristics of benign tumors (4)?
- slow, progressive
- rare mitoses
- normal mitoses
- little necrosis
What are the growth rate characteristics of malignant tumors (4)
- rapid growth
- frequent mitoses
- abnormal mitoses
- necrosis
What is local invasion like for benign tumors (3)?
- no invasion
- cohesive growth
- capsule often present
What is the local invasion like for malignant tumors (3)?
- invasion
- infiltration
- no capsule
variation in cell size
Anisocytosis
variation in nuclear size
anisokaryosis
variation in cell shape
pleomorphism
nuclei become darker due to increased DNA content:
hyperchromasia
Neoplastic cells escape the normal limits of what three things?
- cell division
- stimulatory/inhibitory factors
- apoptosis
If neoplastic cells evade most regulatory mechanisms, why is tumor growth not exponential?
still have irreversible cell cycle arrest and cell death within the tumors
arrests normal cell cycle to allow DNA repair:
p53 (tumor suppressor)
What can help to arrest the cell life cycle at checkpoints G1/S and G2/M?
DNA damage
damaged cells permanently arrest in G1, a result of p53 or retinoblastoma pathways:
senescence
the time before a tumor is clinically detectable:
latent period
Neoplasia has stepwise development. What are the 3 steps?
- initiation
- promotion
- progression
the introduction of an irredversible genetic change by a carcinogen (stable mutation in the DNA) - may allow a selective advantage in the cell:
initiation (1st step in stepwise development of neoplasia)
stimuli (promoters - non mutagenic) cause the growth of the initiated cells - a benign tumor
promotion (2nd step in stepwise development of neoplasia)
Benign tumors become malignant - a complex and poorly understood process of genetic and epigenetic changes in the tumor cells
progression (3rd step in the stepwise development of neoplasia)
the connective tissues (collagen, proteins, glycoproteins, vessels, fibroblasts, and immune cells)
stroma
Stroma may form a capsule around the tumor which helps:
limit spread
an extensive fibrous reaction is often referred to as a:
scirrhous response
a defining characteristic of malignancy:
metastasis
How do malignant tumors spread to different sites in the body?
lymphatics, blood vessels, and/or direct dissemination
penetrate endothelium and access the vessel lumen
intravasation
To move through the body, epithelial cells prefer the __________ while mesenchymal cells prefer ____________.
lymphatics; blood vessels
