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Flashcards in Diagnosis of malignant lesions Deck (44):
1

Specimen collection must be

adequate, representative, and properly preserved

2

Sampling approaches are:

total excision, biopsy, fine needle aspiration, cytology smears

3

Fixation methods

freezing, formaldehyde (paraffin), glutaraldehyde (e- microscope), refrigeration (molecular analysis)

4

H&E stain

H: basic, blue, basophilic: nucleic acids, ribosomes
E: acidic, pink, eosinophilic: cytoplasm, proteins

5

Yellow or brown on H&E stain?

intrinsic cellular pigments, melanin, etc

6

PAS

stain basal laminae (good for malignant lesions)

7

Silver stain

stain reticular fibers

8

Clear structure on H&E?

hydrophobic structures - rich in fat (adipocytes, myelin, golgi)

9

Oil red O stain

stain fats

10

Fine-needle aspiration

aspirating cells and attendant fluid with a small bore needle --> cytological examination

11

Papanicoloau stain is used

to demonstrate cells that have neoplastic characteristics

12

Avidin-Biotin Conjugation ABC/DAB

specimen + incubation with primary Ab for suspected tumor antigen; incubation with secondary ant-IgG conjugate to biotin; + avidin = complexes with biotin (ABC-tissue) + DAB -> chromogen for brown coloring

13

Use of ABC/DAB immunohistochemistry

identification of tumors that resemble each other

14

Immunohistochemistry for intermediate filaments

for malignant tumor identification of origin, tumor cells contain intermediate filaments consistent with their origin

15

Distinguishing class of leukemia and lymphoma

use of immunohistochemistry

16

Immunohistochemistry for tissue-specific or organ-specific antigens

determines origin or metastatic tumor

17

Tumor cells expressing cytokeratins

epithelial origin

18

Tumor cells expressing desmin

muscle origin

19

Immunohistochemistry can distinguish between subtypes of cancer (ER-positive, ER-negative, capthesin D) relies on

overexpression of proteins within the cells

20

Importance of distinguishing subtypes in cancer

determining susceptibility to therapy

21

ER-positive therapy

ER expression; responsive to tamoxifen

22

Tamoxifen action

binds ER, cannot bind coactivators

23

ER-negative therapy

no ER expression; responsive to Herceptin

24

Herceptin action

cancer overexpresses ERBB-> HER2/neu protein; Herceptin binds and inactivates the cell surface GFR

25

Cathepsin-D breast cancer

rapid development of metastases (metastatic potential)

26

FC

gives information about physical and chemical structure of each cell

27

FSC =

cell volume

28

SSC =

shape of nucleus, cytoplasmic granule types, membrane roughness

29

Fluorescence in FC

presence (relative quantity) or antigen on surface

30

FC used to

classify leukemia and lymphoma, detection of ploidy

31

aneuploidy is associated with

poorer prognosis for cancer patient

32

Primary modality for cancer diagnosis

histology

33

FISH

used to differentiate B and T cell malignancies, by detection of specific translocations that activate oncogenes

34

FISH procedure

DNA probe for specific sequence + sample + fluorophores --> reveals translocations and other chromosomal rearrangements

35

Array based comparative Hybridization

examine the molecular profile (quantify the expression of large numbers of genes) of different tumors using mRNA levels -> gives clues of potential over expression of tumor markers

36

Array based comparative Hybridization complications

uses mRNA which do not directly correspond with proteins; this is due to rate of translation, protein breakdown, and protein export

37

Complications of using tumor markers

low specificity/sensitivity, used as supporting evidence

38

Carcinoembryonic antigen (CEA)

glycoprotein produced in embryonic tissues of the digestive tract, pancreas, and liver; may be elevated in colorectal and pancreatic carcinoma

39

CEA tumor marker use

because it is also elevated in certain non-malignant disease, there is LOW specificity and sensitivity; but may be useful as a prognostic indicator (CEA increased with tumor size)

40

Alpha fetal protein

glycoprotein produced early in fetal life by the yolk sac, liver, and GI tract; may be elevated in hepatocellular carcinoma and germ cells of the testis

41

PSA

prostate specific membrane antigen used as a marker for prostate cancer

42

HCG

testicular tumor marker

43

CA125

tumor marker for ovarian tumors

44

Main factors for prognosis and therapy

tumor size, metastases