Histopathology, Histotechniques, Cytology, and General Pathology

Flashcards testing definitions, processes, reagents, equipment, staining methods, and pathology principles from the histopathology review transcript.

What is Histopathology?

A branch of anatomical pathology that deals with the study of diseases in a given tissue or organ.

What does Histotechniques encompass?

The preparation, processing, and staining of tissue sections for microscopic study to be interpreted by the pathologist as either malignant or benign.

What are the retention requirements for specimens and records in histopathology?

Specimens: 1 month to 1 year; Tissue blocks: 3 years to 10 years; Slides: Indefinite; Records: Permanent; Result forms: Triplicate.

What is the section thickness range required for sectioning preparations?

$3.0\text{--}5.0\,mm$ thickness.

What is the primary disadvantage of the teasing/dissociation method in fresh tissue examination?

Anatomical relationship is destroyed.

What technique uses duplicate sections of alcohol-fixed tissues and a polarizing microscope to locate mineral deposits (spodogram)?

Microincineration.

What basic equation is used for reagent dilution preparations?

$$V_1C_1 = V_2C_2$$

What is the required fixative volume ratio relative to tissue size during fixation?

1:20x volume of tissue.

What fixative is most widely used for Electron Microscopy?

Glutaraldehyde.

Which fixative is described as the most rapid fixative and is recommended for urgent biopsies and chromosomes?

Carnoy's Fluid.

Which fixative is the most common fixative and is used for renal tissue, connective tissue, muscle, and fibrin?

Mercuric Chloride.

What fixative solidifies at $17^\circ\text{C}$ and precipitates chromosomes and chromatin?

Glacial Acetic Acid.

What are the standard temperature and time factors for decalcification?

Temperature: Room Temperature ($18\text{--}30^\circ\text{C}$); Time: 24-48 hours.

Which decalcifying agent is the most rapid decalcifier recommended for urgent works?

Phloroglucin Nitric Acid.

What are the 10 steps in routine tissue processing in sequential order?

1. Fixation/Preservation, 2. Dehydration, 3. Clearing/Dealcoholization, 4. Infiltration/Impregnation, 5. Embedding/Casting/Blocking, 6. Trimming, 7. Section-cutting, 8. Staining, 9. Mounting, 10. Labelling.

What dehydrating agent is preferred for blood and tissue films and smears?

Methanol.

What exposure side-effect is associated with Tetrahydrofuran after 6 months?

Conjunctival irritation.

Which clearing agent is carcinogenic, causing bone marrow damage and aplastic anemia?

Benzene.

What embedding medium is composed of Purified Pyroxylin Nitrocellulose and used for hollow organs, brain, and whole eyes?

Celloidin/Collodion.

Which embedding mold consists of two L-shaped heavy metal or brass units and is recommended for routine purposes?

Leuckhart's embedding mold.

Which microtome is most commonly used for routine paraffin-embedded sections?

Rotary (Minot) microtome.

Which microtome knife type is recommended for frozen sections and celloidin embedded sections?

Plane-Wedge knife ($100\,mm$).

What are the standard microtome knife clearance and bevel angles?

Clearance angle: $5\text{--}15^\circ$; Bevel angle: $27\text{--}32^\circ$.

How do honing and stropping differ in terms of stroke direction and motion?

Honing moves Heel-to-Toe in a Zigzag motion; Stropping moves Toe-to-Heel in a Zigzag motion.

What is the simplest method of differential staining of collagen?

Van Gieson.

Which stain is the most reliable and specific histochemical staining technique for DNA?

Feulgen's stain.

What histochemical stain is used for the demonstration of carbohydrates, specifically glycogen?

Periodic Acid Schiff (PAS).

Which fluorescent stain allows discrimination between dead and living cells based on green and red fluorescence?

Acridine Orange (DNA: green fluorescence; RNA: red fluorescence).

What stain technique stains melanin black?

Masson Fontana Technique.

What ingredient in Mayer's Egg Albumin prevents the growth of mold?

Thymol.

What is the capacity of a Koplin Jar?

5 to 9 slides.

What is the refractive index of Canada Balsam?

1.524

What error causes horizontal or parallel lines (chatters) across a cut tissue section, and how is it remedied?

Caused by improper knife angle or tissue hardness; remedied by treating with phenol during processing, collodionizing, or reducing knife tilt.

According to Broder's Classification of Tumor Grade, what are the percentages of cells for Grade III?

25-50% differentiated cells and 50-75% undifferentiated cells.

Which cells found in cervico-vaginal smears present a characteristic 'fried-egg' appearance?

Parabasal cells.

What cytological appearance is characteristic of endocervical glandular cells?

Honey-comb appearance.

How is Class IV defined in Papanicolaou's (Pap's) cytologic evaluation?

Cytologic picture strongly suggestive of malignancy.

What is the definition of Metaplasia?

A reversible change involving the transformation of one type of adult cell to another.

What are the five cardinal signs of inflammation?

1. Rubor (Redness), 2. Tumor (Swelling), 3. Calor (Heat), 4. Dolor (Pain), 5. Functiolaesa (Diminished Function).

What type of necrosis involves rapid total enzymatic dissolution of cells with complete destruction, typically caused by bacterial infection?

Liquefaction or Colliquative necrosis.