Benign v. Malignant Tumors

Question 1

What are the 4 main differences between benign and malignant tumors?

Answer 1

Differentiation
Growth pattern
Invasion
Metastasis

Question 2

Differentiation

Answer 2

Extent where parenchymal cells resemble comparable normal cells

Question 3

Differentiation of tumors

Answer 3

Benign: well differentiated
Malignant: well to poorly differentiated

Question 4

Dysplasia

Answer 4

Disordered growth (usually epithelial)
Sometimes a preneoplastic change

Question 5

Anaplasia

Answer 5

Loss of differentiation of cells
Revision of cells to more primitive/ less diff. form

Question 6

Anaplasia cytologic characteristics

Answer 6

Pleomorphism
Abnorm. nucleus, large nucleoli
↑ mitotic figures
Loss of polarity
Formation of tumor giant cells

Question 7

Pleomorphism

Answer 7

Variation of size and shape of cells:
Nuclear size and shape: anisokaryosis and poikilokaryosis
Cytoplasmic size and shape: anisocytosis, poikilocytosis

Question 8

Loss of polarity

Answer 8

Cell orientation disturbed
Cells grow in anarchic or chaotic disorganized way

Question 9

Tumor giant cells

Answer 9

Huge polymorphic nucleus or multiple
Not the same as normal tissue giant cells

Question 10

With better differentiation…

Answer 10

The more the cell will resemble normal counterparts

Question 11

What happens in functional differentiation with anaplasia?

Answer 11

↑ anaplasia → enzymes and specialized pathways lost → cells undergo functional simplification

Question 12

Effects of tumors

Answer 12

Elaborate fetal proteins (Ags) not produced by norm. cells
Cancers of non-endocrine origin secrete endocrine like hormones
Paraneoplastic syndromes

Question 13

Bengin tumors

Answer 13

Localized at site of origin
Can’t invade, infiltrate, or metastasize
Develop CT capsule

Question 14

Malignant tumors

Answer 14

Progressive infiltration
Invasion and destruction of surrounding tissue
No encapsulated

Question 15

Carcinoma in situ

Answer 15

Malignant tumor that doesn’t invade beyond the BM

Question 16

Factors involved in resistance to invasion by tumors

Answer 16

Physiological characteristics of the matrix
Biologic stability and slow turnover (cartilage)
Inhibitory substances (anti-angiogenesis factors)

Question 17

Metastasis

Answer 17

Tumor implants discontinuous with the primary tumor
Indicated malignancy
All cancers don’t

Question 18

Metastasis pathways of spread

Answer 18

Seeding of body cavities (needle spreading cancer cells to other places)
Lymphatic spread
Hematogenous spread

Question 19

Lymphatic spread

Answer 19

LN → cells replicate/ destroyed → inflamm. response
Common with carcinomas

Question 20

Hematogenous spread

Answer 20

Mostly sarcomas
Spread though venous flow
Arterial spread can occur via pulmonary capillaries, arterial-venous shunts or pulmonary nets

Question 21

__________ is the hallmark of malignant tumors

Answer 21

Metastasis

Question 22

Requirements for metastasis

Answer 22

Break from primary mass
Pass through CT to vessels
Enter BVs or lymphatics
Set up secondary growth at new site

Question 23

Metastatic cells interactions with the ECM

Answer 23

Ability to attach to, degrade and penetrate ECM
ECM: BM and interstitial CT

Question 24

Basement membranes

Answer 24

Separates endothelial and epithelial cells from ICT
Meshwork of collage 4, laminin, proteoglycans

Question 25

Laminin

Answer 25

Glue that binds epithelial cells and collagen 4

Question 26

Interstitial CT

Answer 26

Collagen 1
Fibronectin (adhesion)
Proteoglycans (retain water in tissues, maintains shape and CT)

Question 27

Invasion

Answer 27

1. Loosening of intercellular junction (dissociation)
2. Proteolytic enzymes secreted and degrade matrix components of ECM
3. Migration and invasion of tumor cells to degraded zone via attachment to laminin and fribronectin