HISTOPATH

What is the most common form of necrosis?

Coagulation necrosis

2.

What tissues are commonly affected by coagulation necrosis?

Myocardium, lungs, spleen, and kidneys

3.

What is the hallmark appearance of coagulation necrosis?

Tombstone appearance

4.

What type of necrosis is seen in the brain and spinal cord?

Liquefaction necrosis

5.

What is another name for liquefaction necrosis?

Autolysis or heterolysis

6.

What is the appearance of caseous necrosis?

Soft, white or yellow, cheese-like and crumbly

7.

What diseases are associated with caseous necrosis?

Tuberculosis, syphilis, lymphogranuloma inguinale, tularemia

8.

Gangrenous necrosis is usually secondary to what condition?

Ischemia with superimposed infection

9.

What type of gangrene results from arterial occlusion?

Dry gangrene

10.

What type of gangrene is associated with bacterial infection?

Wet gangrene

11.

What is produced in gangrenous necrosis by Clostridium perfringens?

Sulfide gas

12.

What necrosis results from pancreatic lipase release?

Fat necrosis

13.

What does steatosis commonly affect?

The liver (fatty liver

What does Rubor signify?

Redness

15.

What causes Rubor?

Arteriolar and capillary dilation

16.

What does Tumor indicate?

Swelling

17.

What causes Tumor?

Increased capillary permeability

18.

What does Calor mean?

Heat

19.

What causes Calor?

Increased blood content at the injury site

20.

What does Dolor mean?

Pain

21.

What causes Dolor?

Pressure on sensory nerves

22.

What does Functio Laesa mean?

Loss of function

What is the first and most critical step in histotechnology?

Fixation

24.

When should fixation ideally begin?

Within 20–30 minutes after interruption of blood supply

25.

What is the primary aim of fixation?

Preserve the morphological and chemical integrity of the cell

26.

What is the secondary aim of fixation?

Harden and protect tissue from trauma of handling

27.

What is the ideal tissue-to-fixative ratio?

1:10 to 1:20

28.

What is the most used routine fixative?

10% formalin (neutral buffered)

29.

What stabilizer is added to formalin to prevent formic acid formation?

10% methanol

30.

What artifact is formed by acidic formalin?

Acid formaldehyde hematin (brown pigment)

What is the purpose of dehydration in tissue processing?

To remove water from the tissue before embedding

48.

What are commonly used dehydrating agents?

Alcohols like ethanol, methanol, and isopropanol

49.

Which alcohol is considered the best dehydrating agent?

Ethanol

50.

What dehydrating agent is both explosive and toxic?

Acetone

What is the purpose of clearing in tissue processing?

To remove the dehydrating agent and make tissue transparent

52.

What is the most commonly used clearing agent?

Xylene

53.

What clearing agent is safer but slower than xylene?

Chloroform

54.

What happens if clearing is incomplete?

Poor paraffin infiltratioN

What is the purpose of infiltration?

To replace the clearing agent with embedding medium (e.g., paraffin)

56.

What is the most common infiltration medium?

Paraffin wax

What is the process of enclosing tissue in a supporting medium?

Embedding

58.

What is the ideal temperature for paraffin embedding?

2–5°C above melting point of wax

59.

What is the ideal orientation for embedding skin specimens?

Epidermis should face down

60.

Why is embedding important in tissue processing?

It supports tissue for sectioning

What is the instrument used to cut thin tissue sections?

Microtome

62.

What is the most commonly used microtome in histopathology?

Rotary microtome

63.

What microtome is used for large or hard tissues like bone?

Sliding microtome

64.

What microtome is used for frozen sections?

Cryostat

65.

What is the usual thickness of paraffin sections?

4–6 micrometers

66.

What is the usual thickness of frozen sections?

10–15 micrometers

67.

What solution is used to float paraffin ribbons before mounting?

Warm water in a flotation bath

68.

What is the best temperature for the flotation bath?

5–10°C below the melting point of wax

69.

What causes wrinkling of paraffin ribbons?

Dirty knife, incorrect clearance angle, or poor wax infiltration

70.

What is used to clean the microtome knife?

Xylene followed by alcohol

What is the routine stain used in histopathology?

Hematoxylin and Eosin (H&E)

72.

What part of the cell does hematoxylin stain?

Nucleus (basophilic structures)

73.

What color does hematoxylin produce?

Blue to purple

74.

What part of the cell does eosin stain?

Cytoplasm and extracellular proteins

75.

What color does eosin produce?

Pink to red

76.

What is used as a mordant in H&E staining?

Aluminum salts (e.g., alum)

77.

What is the purpose of "bluing" in H&E staining?

To change reddish hematoxylin to a stable blue color

78.

What solution is commonly used for bluing?

Ammonia water or Scott’s tap water

What stain is used for carbohydrates and glycogen?

Periodic Acid-Schiff (PAS)

80.

What color does PAS stain glycogen?

Magenta

81.

What is the stain for acid-fast bacilli (e.g., TB)?

Ziehl-Neelsen stain

82.

What stain is used for reticulin fibers?

Gomori’s silver stain

83.

What stain is used for collagen?

Masson's trichrome

84.

What stain is specific for amyloid deposits?

Congo red

85.

Under polarized light, how does Congo red-stained amyloid appear?

Apple-green birefringence

What is the purpose of mounting in histopathology?

To preserve stained tissue and provide support for microscopy

87.

What is the most common mounting medium?

DPX (Distyrene Plasticizer Xylene)

88.

What is used to remove water before mounting?

Absolute alcohol (dehydration step)

89.

What is used to remove alcohol before mounting?

Xylene (clearing agent)

90.

What should you avoid during coverslipping to prevent bubbles?

Trapping air under the coverslip

What causes chatter (venetian blind artifact) in sections?

Over-hardened tissue or dull knife

92.

What artifact results from incomplete dehydration?

Poor staining or uneven infiltration

93.

What does excessive clearing cause?

Brittle tissue

94.

What causes tissue lifting from slides?

Inadequate adhesive or incomplete drying

95.

What artifact appears as black granules from mercury fixatives?

Mercury pigment

96.

What is the remedy for mercury pigment?

Iodine followed by sodium thiosulfate

What is the study of individual cells to diagnose disease?

Cytopathology

98.

What is the process of examining cells shed from body surfaces?

Exfoliative cytology

99.

What is the most common use of exfoliative cytology?

Cervical smear (Pap smear)

100.

Who is the father of exfoliative cytology?

George Papanicolaou

101.

What stain is used in Pap smear?

Papanicolaou stain

102.

What are common fixatives for Pap smears?

95% ethanol or spray fixatives

103.

What is FNAB in cytology?

Fine Needle Aspiration Biopsy

104.

What is the main advantage of FNAB?

Minimally invasive and rapid diagnosis

What is the proper sequence of tissue processing steps?

Fixation → Dehydration → Clearing → Infiltration → Embedding

106.

What type of tissue processor is most commonly used in histology labs?

Automatic tissue processor

107.

What is the total time for routine tissue processing?

Around 12–16 hours (overnight)

108.

What temperature is paraffin wax typically maintained at in tissue processors?

56–60°C

109.

What can result from incomplete dehydration?

Poor infiltration and tissue shrinkage

110.

What agent follows dehydration in the processing sequence?

Clearing agent (e.g., xylene

What type of biopsy removes a small part of the lesion?

Incisional biopsy

112.

What biopsy removes the entire lesion?

Excisional biopsy

113.

What biopsy uses a hollow needle to collect tissue?

Core needle biopsy (CNB)

114.

What biopsy uses suction to obtain cells or fluid?

Fine needle aspiration biopsy (FNAB)

115.

What is the ideal gauge for FNAB needles?

22–25 gauge

116.

What biopsy method is used for prostate or breast core samples?

Trucut biopsy