T25 - Tumor Growth

Question 1

What five factors are used to assess tumors?

Answer 1

demarcation

induration

differentation

rate of growth

distant spread (metastasis)

[DIDRM]

Question 2

Grossly and by palpation, what are the features of benign tumors? (4)

Answer 2

sharp, distinct margins

freely movable by palpation

visible boundary between normal tissue and tumor

encapsulated

Question 3

Describe how benign tumors grow. (2)

Answer 3

slow expansile growth

compresses surrounding tissue as it grows

Question 4

Describe the capsule of benign tumors.

Answer 4

consists of dense type I collagen produced by fibroblasts

Question 5

The capsule of benign tumors is produced in response to

Answer 5

pressure from adjacent masses

Question 6

The presence of a capsule implies

Answer 6

slow and non-invasive tumor growth

Question 7

Grossly, what are the features of malignant tumors? (4)

Answer 7

ill-defined margins

indistinct boundary between normal tissue and tumor

jagged/stellate configuration

fixed to surrounding tissue

Question 8

There are exceptions to the notion that malignant tumors are not well circumscribed. How can malignant tumors be definitively identified on a microscopic scale?

Answer 8

malignant tumors almost always exhibit small foci of penetration through capsule w/ invasive growth into vasculature or surrounding tissue

Question 9

Define induration.

Answer 9

firmess of tumor on palpation

Question 10

Fibroblasts in tumors often produce

Answer 10

abnormal, densely collagenous stroma that gives tumor firm/rock-hard/indurated texture

Question 11

Define desmoplasia. (2)

Answer 11

abnormal stroma production by tumor leading to induration on palpation

“lots of cancer stuff + fiber stuff” [from tutoring]

Question 12

The finding of induration in a mass suggests

Answer 12

the mass is an invasive cancer.

Question 13

What is a tumor stroma?

Answer 13

tumor (with neoplastic cells) + recruited “normal” cells such as fibroblasts

Question 14

Define differentiation.

Answer 14

degree to which a tumor resembles the normal tissue cells from which it arose

Question 15

What is the relationship between differentiation and malignancy? (2)

Answer 15

benign tumors are very well-differentiated

in other words, degree of differentiation is inversely correlated with tumor aggressiveness

Question 16

Describe the key architectural indicator of differentiation in epithelial cells. (2)

Answer 16

epithelial cells are polarized → basal and apical have different functions

malignant tumors show loss of polarity → increased stratification of epithelium

Question 17

What is the key indicator of morphologic differentiation in adenocarcinomas?

Answer 17

loss of ability to make well-formed glands

Question 18

What is cellularity?

Answer 18

density of cells, seen in tissue section as number of cells per unit area

Question 19

What is the relationship between cellularity and differentiation? (4)

Answer 19

poorly-differentiated = more malignant → smaller cells → increased cellularity → increased density of nuclei

Question 20

Describe nuclear morphology in tumors.

Answer 20

greater variability in size/shape = pleomorphism

Question 21

What causes nuclear pleomorphism?

Answer 21

variations in DNA content (aneuploidy) in tumor cells

Question 22

How do tumor nuclei stain by H&E?

Answer 22

stain more darkly = hyperchromasia

Question 23

What is the significance of the nuclear to cytoplasmic ratio?

Answer 23

cytoplasm reduced in poorly-differentiated cells → increased DNA content → higher nuclear to cytoplasmic (NC) ratio

Question 24

How does abnormal DNA content in tumor cells manifest?

Answer 24

manifested as abnormal mitotic figures, such as tripolar mitoses

Question 25

Describe the nucleoli of tumor cells.

Answer 25

prominent nucleoli due to need for increased metabolic activity and protein synthesis

Question 26

What is functional differentiation?

Answer 26

degree to which cells produce normal cellular products

Question 27

Give four examples of cellular products that can be used to assess functional differentiation.

Answer 27

mucin (glandular cells) keratin (squamous cells) hormones (endocrine cells) extracellular matrix (bone/cartilage cells)

Question 28

List four key morphologic characteristics that can be used to assess malignancy.

Answer 28

polarity gland formation cellularity pleomorphism

Question 29

What is anaplasia?

Answer 29

extreme degree of loss of differentiation

Question 30

What is a synonym for anaplasia?

Answer 30

de-differentiation

Question 31

What are the four primary features of anaplasia?

Answer 31

total lack of tissue organization extreme cell/nuclear pleomorphism large/hyperchromatic/bizzare nuclei abnormal mitotic figures [TELA]

Question 32

What is the relationship between rate of growth and differentiation?

Answer 32

rate of growth inversely correlated with degree of differentiation

Question 33

Give two examples of tumors that are metastatic at an early stage.

Answer 33

melanoma small cell carcinoma of the lung

Question 34

What are the four primary routes of metastasis?

Answer 34

direct seeding lymphatic spread hematogenous spread transplantation

Question 35

What is direct seeding?

Answer 35

spread within body via detachment and subsequent implantation in physically contiguous manner

Question 36

What is peritoneal seeding? (2)

Answer 36

when ovarian tumors spread directly into the peritoneal cavity an example of direct seeding

Question 37

What is the major mode of spread of carcinomas?

Answer 37

lymphatic spread

Question 38

What is the likely site of lymph node metastasis for the breast?

Answer 38

axillary nodes

Question 39

What is the likely site of lymph node metastasis for the lung? (2)

Answer 39

hilar nodes peribronchial nodes

Question 40

What is the likely site of lymph node metastasis for the testis?

Answer 40

paraaortic nodes

Question 41

What is the likely site of lymph node metastasis for leg skin?

Answer 41

inguinal lymph nodes

Question 42

What is the major mode of spread for sarcomas?

Answer 42

hematogenous spread

Question 43

Hematogenous spread is the major mode of spread for which tumor(s)? (2)

Answer 43

major mode for sarcomas common mode for carcinomas

Question 44

Hematogenous spread occurs through which structure?

Answer 44

occurs through venous drainage

Question 45

How do intestinal tumors metastasize to the liver?

Answer 45

via the portal system

Question 46

How do prostatic tumors metastasize to the lower spine?

Answer 46

via vertebral plexus

Question 47

List two tumors that tend to metastasize in an idiosyncratic/noteworthy manner.

Answer 47

lung tumors → adrenals renal cell carcinoma → renal vein → inferior vena cava → right side of heart

Question 48

Overall, what are the four most common sites of metastasis?

Answer 48

lymph nodes lung liver bone

Question 49

Overall, what are the three least common sites of metastasis?

Answer 49

skeleta muscle heart GI tract

Question 50

Why might transplantation of tumor cells be helpful? (2)

Answer 50

give tumor cells access to new territory rarely done in practice

Question 51

Why are testicular masses never biopsied?

Answer 51

testis surrounded by tough fibrous capsule, the tunica albuginea, which if broken would give tumor opportunity to spread into scrotal sac and peritoneal cavity

Question 52

Testicular masses are never biopsied. What is the only option for obtaining diagnostic tissue from a testicular mass?

Answer 52

orchiectomy

Question 53

Give an example of a neoplasm that is locally aggressive but does not metastasize.

Answer 53

basal cell carcinoma of skin

Question 54

Give an example of a benign tumor that produces stable deposits at distant sites.

Answer 54

benign metastasizing leiomyomatosis

Question 55

What are sampling issues?

Answer 55

the idea that only a portion of tumor cells are imaged and visualized with any histologic workup — and that there is therefore an upper theoretical limit on the accuracy of the diagnosis

Question 56

What is grading?

Answer 56

assessment of level of histologic differentiation

Question 57

What is the relationship between tumor grading and tumor differentiation?

Answer 57

lesser differentiation = higher grading = more aggressive

Question 58

What are the tumor grading intervals? (2)

Answer 58

low, intermediate, or high grades -*or*- grades I-IV

Question 59

What is staging?

Answer 59

assessment of physical extent of disease/tumor spread

Question 60

What is the most common grading/staging scheme?

Answer 60

TNM system

Question 61

What is the basis of the TNM system?

Answer 61

T = size of primary (T1, T2, T3, T4) N = regional lymph node involvement (N1, N2, N3) M = distant metastasis (M0 [not present] or M1 [present])

Question 62

TNM combinations correspond to which five stages?

Answer 62

Stage 0 Stage I Stage II Stage III Stage IV

Question 63

Describe what Stage 0 means.

Answer 63

carcinoma in situ

Question 64

Describe what Stages I-III mean.

Answer 64

more extensive disease greater tumor size spread of cancer to nearby lymph nodes spread to adjacent organ [*progress from Stage I* → *II* → *III* *as severity increases*]

Question 65

Describe what Stage IV means.

Answer 65

cancer has spread to another organ (distant metastasis)

Question 66

TNM criteria vary based on the tumor. If grading and staging are discrepant, which parameter is used to assess prognosis?

Answer 66

staging is more important — in other words, stage is a better predictor of clinical progression than grade

Question 67

Differentiate between embryonic and adult stem cells in terms of potency.

Answer 67

embryonic stem cells are _totipotent_ adult stem cells are _multipotent_

Question 68

What is a niche?

Answer 68

microenvironment composed of adult stem cell + supporting niche cells

Question 69

What is the recent hypothesis relating cancer stem cells? (2)

Answer 69

tumors harbor cancer stem cells analogous to adult stem cells the cancer stem cells are rare undifferentiated cells that are capable of replenishing themselves and differentiating to form a tumor

Question 70

Which three signaling pathways regulate adult stem cells in normal development and tissue homeostasis?

Answer 70

Notch WNT hedgehog

Question 71

What is the limitation of conventional chemotherapy on cancer stem cells?

Answer 71

conventional chemotherapy _cannot_ kill cancer stem cells because cancer stem cells mimic every cell in the body

Question 72

What is renewal?

Answer 72

formation of two daughter stem cells

Question 73

What is maintenance?

Answer 73

formation of one daughter stem cell + one differentiated cell

Question 74

What is differentiation?

Answer 74

formation of 2 differentiated cells

Question 75

The presence of keratin pearls indicates what kind of malignancy?

Answer 75

keratin pearls = **squamous cell carcinoma**