Pathology Neoplasia

Question 0

Explain the significance of glucose 6-phosphate dehydrogenase in determining clonality.

Answer 0

G6PD active isoform ratio is 1:1 in females

• In neoplastic growth, clonality is monoclonal so G6PD ration is disturbed
• In hyperplastic growth, ratio is preserved

Question 1

What are the characteristics of neoplasia? What differentiates it from dysplasia? Hyperplasia?

Answer 1

Neoplasia: unregulated, irreversible, and monoclonal

• Hyperplasia is polyclonal and reversible
• both dysplasia and neoplasia have mutations but dysplasia is reversible

Question 2

Clonality of B lymphocytes - light chain phenotype

Answer 2

• Normally light chain kappa to lambda ratio is 3:1
• Ratio is maintained in hyperplastic growth (reactive hyperplasia to infection)
• In neoplastic growth (lymphoma) ratio is disturbed - >6:1 or is inverted (kappa to lambda ratio 1:3)

Question 3

Reason for lymph node enlargement

Answer 3

1. Metastatic cancer
2. Lymphoma
3. Infection (reactive hyperplasia)

Question 4

Carcinoma

Answer 4

implies epithelial origin
-generally spread lymphatically; exceptions: RCC- renal vein, HCC-hepatic vein, follicular carcinoma of thyroid, choriocarcinoma

Question 5

Sarcoma

Answer 5

implies mesenchymal origin

-generally spread hematogenously

Question 6

Cachexia

Answer 6

weight loss, muscle atrophy, and fatigue that occur in chronic disease (cancer, AIDS, heart failure, TB)
-mediated by TNF-a, IFN-gamma, IL-6

Question 7

Leading causes of death in adults

Answer 7

1. Cardiovascular disease
2. cancer
3. cerebrovascular disease

Question 8

Leading causes of death in children

Answer 8

1. accidents
2. cancer
3. congenital abnormalities

Question 9

Most common cancer by incidence in adults

Answer 9

1. Breast/prostate
2. lung
3. colorectal

Note: squamous cell and basal cell carcinoma very common!

Question 10

Most common causes of cancer mortality in adults

Answer 10

1. lung
2. breast/prostate
3. colorectal

Question 11

Screening: Pap smear

Answer 11

: detects cervical squamous cell dysplasia (CIN- cervical intraepithelial neoplasia) before it becomes carcinoma

Question 12

How many divisions occur before the earliest clinical symptoms of cancer arise?

Answer 12

30 divisions

Question 13

Screening: mammography

Answer 13

:detect in situ breast cancer before it invades or invasive carcinoma before it becomes clinically palpable
- mammography can detect tumors as small as 1 cm, whereas palable tumors are usually at least 2 cm

Question 14

Screening: PSA and DRE

Answer 14

:prostate specific antigen and digital rectal exam - detects prostate carcinoma before it spreads
Note:
-BPH usually occurs in the center of the prostate and may surround the urethra so clinical symptoms may appear
-prostate cancer usually occurs in the posterior peripheral zone of the prostate = asymptomatic until very large; DRE to feel posterior prostate

Question 15

IHC stain- keratin positive cells

Answer 15

epithelium –> carcinoma

Question 16

IHC Stain- vimentin positive cells

Answer 16

Mesenchyme –> sarcoma

Question 17

IHC stain- desmin positive cells

Answer 17

muscle —> rhabdomyosarcoma

Question 18

IHC stain- GFAP positive cells

Answer 18

neuroglia

Question 19

IHC stain - neurofilament positive cells

Answer 19

neurons

Question 20

IHC stain- PSA positive cells

Answer 20

prostatic epithelium

Question 21

IHC stain- ER positive cells

Answer 21

breast epithelium

Question 22

IHC stain- thyrogloblulin positive cells

Answer 22

thyroid follicular cells

Question 23

IHC stain- chromogranin positive cells

Answer 23

neuroendocrine cells

Question 24

IHC stain: S-100 positive cells

Answer 24

melanoma, schwannoma, and langerhans cell histocytosis

Question 25

Tumor grade

Answer 25

: microscopic assessment of differentiation; how closely do the cells look like the tissue of origin
-usually from 1-4, where 1(low grade) is well differentiated and 4(high grade) is poorly differentiated

Question 26

Tumor stage

Answer 26

:assessment of size and spread of cancer; based on clinical (c) or pathology (p) findings ex. cT3N1M0
T-tumor size
N- regional nodal involvement
M- distant metastasis; most important prognostic factor