Tissue sampling

Question 1

What is Cytology?

Answer 1

• Free cells on slide
• Individual cell morphology
• Higher magnification
• Faster turnaround time
• Less invasive
• Can do in practice

Question 2

What is Histopathology?

Answer 2

• Tissue is fixed, embedded in paraffin, sliced and placed on slide
• Architecture of tissue
• Lower magnification
• More invasive
• Longer turn around time
• Sent off

Question 3

What is a fine needle aspirate?

Answer 3

• Using a small (fine) needle to otain a tissue sample
• Sometimes reffered to as a “fine-needle biopsy”
  
  • possibly misleading term
• Goal is to obtain a representative sample of the cells in that location
• Some lesions exfoliate well and therefore lend themselves to FNA whereas others do not exfoliate well and are better suited for biopsy methods

Question 4

What is an Incisional Biopsy

Answer 4

• surgical removal of a piece of a mass
  
  • Could be a sliver, wedge, or a punch
• Goal is to obtain tissue that is representative of the disease process

Question 5

What is an Excisional Biopsy?

Question 6

How to mak a differential list?

Answer 6

• DAMNIT-V (Or VITAMIN D)
• D: Degenerative, Developmental
• A: Anomalous, Autoimmune
• M: Metabolic, Mechanical
• N: Neoplastic, Nutritional
• I: Infl mmation, Infectious, Immune-mediated, Idiopathic, Inherited, Iatrogenic
• T: Toxic, Traumatic
• V: Vascular

Question 7

What are the Techniques for Fine Needle Aspirate?

Answer 7

1. Woodpecker/Sewing Machine Method
   
   • Preffered for solid masses
   • Results in less sample cell trauma
2. Aspiation method
   
   • Preffered for fluid filled lesions
   • Can attempt for solid masses if sewing machine method fails

Question 8

What is the Woodpecker/Sewing Machine method?

Answer 8

• inserting and removing the needle rapidly from the lesion
• Goal is to try to fill the needle with cells from the lesion
• Need:
  
  • 22 guage needle
    
    • larger = more tissue trauma and hemorrhage in sample
    • smaller = more likely to bend
  • 3 - 6 cc syringe
  • Clean glass slides

Question 9

How is the Woodpecker/sewing machine method done?

Answer 9

1. Needle without syringe is inserted into the lesion
2. Needle is then moved up & down within the lesion several times to exfoliate cells
3. Syringe is filled with ari, tehn attached to the needle, & sample is blown out of the needle onto the slide
4. The sample is then spread using a second clean glass slide

Question 10

What is a Mast Cell Tumor?

Answer 10

• Tend to occur in skin
• Boxers at a higher risk for developing
• Lesions can be red/purple in color
• Lesions can also appear to come and go
• Mast cells contain histamine
  
  • The histamine results in inceased blood flow, swelling, and the changes we see in the skin when they degranulate

Question 11

How is the Aspiration method done?

Answer 11

1. Needle with syringe is attached is inserted into the lesion
2. Plunger is pulled back sightly to create negative pressure
3. With th negative presure maintained, the needle is moved up & down within the lesion several times to exfoliate cells
4. Negative pressure is released and the needle is removed from the lesion
5. The syringe is disconnected from the needle, filled with air, and then reconnected to the needle
6. The sample is then blown out onto a slide and then spread with a second slide

Question 12

What are the external limph nodes that can be assessed?

Answer 12

1. Submandibular
2. Superficial Cervical (AKA pre-scapular)
3. Axillary* not palpable
4. Inguinal* not palpable
5. Popliteal

Question 13

How is a patient prepared for a punch biopsy?

Answer 13

• Local anesthesia is generall sufficent but some cases may require sedation or full anesthesia
• For most skin lesions, we do NOT prep the area before biopsy
  
  • May disrupt the skin lesion (pustule, crust, scab, etc) and make it more difficul for the pathologists to interpret

Question 14

How is a punch biopsy taken?

Answer 14

1. Punch is placed on the surface and rotated in one direction whle gentle pressure is applied
2. Biopsy is lifted (with needle or gentle use of forceps)
3. Deep margin is cut using scissors or scalpel blade

Question 15

Do punch biopsy sites need to be closed?

Answer 15

• Closure may not be needd if the punch was very small OR the tissue is tightly adhered or friable (gums)
• Can generally be closed with a single interrupted or a cruciate

Question 16

What is done with the biopsy?

Answer 16

• After removal, the sample tissue is placed in a sealed container with 10% formalin
  
  • 15-20x the volume of formaline to volume of tissue
• Complete appropriate submission form
• Sample is then shipped to a diagnostic lab for processing and interpretation

Question 17

What is a tension suture pattern?

Answer 17

• Can be short or long term
  
  • May be placed to allow for placement of single interrupted sutures in areas of high tension, then immediately removed after closure
  • Can remain in place longer if there is concern that a non-tension pattern may not hold the incision closed

Question 18

What is the horizontal Mattress pattern

Answer 18

• Can be interrupted or continuous, most ofeten interrupted
• Quickpattern
• Used in areas of tension
  
  • somtimes used with rubber stents or puttons
• Can also assist with hemostasis

Question 19

What are the disadvantages of the Horizontal mattress pattern

Answer 19

• Potential disruption to blood supply
• Potentil tissue strangulation
• Can result in significant eversion of margins

Question 20

What is the Verticle Mattress pattern

Answer 20

• Interrupted pattern
• Stronger han horizontal mattress
• Less disruption ob blood supply
• Preferred pattern for skin with tension
• Less skin eversion than with horizontal matress

Question 21

What are the disadvantages of the vertical Mattress Pattern?

Answer 21

• More needle manipulation to create pattern, more time per suture
• More tissue swelling because of multiple needle passes
• Not as effective at hemostasis compared to horizontal mattress

Question 22

What is an excisional Biopsy

Answer 22

• Complete removal of teh visible mass + some grossly normal tissue “margins”
• Intent is to be curative, or to ensure entrie mass is removed
• The amount of visibly normal tissue will vary depending on the nature of the lesions
  
  • 1-2 mm are approprate for some lesions
  • 3+ cem are needed for others

Question 23

What is a dirty margin?

Answer 23

• there is tumor in your margin
  
  • there is tumor in your patient

Question 24

What is a narrow margin?

Answer 24

• Tumor is not in your margin but very close

Question 25

What is a wide/complete margin

Answer 25

* Appropriate distance between tumor edge and surgery edge was acheived

Question 26

Is the patient away during excisional biopsy?

Answer 26

* Sedation and/or anesthesa are generally needed for excisional biopsies * Local blocks are still performed to help with anesthetic depth

Question 27

How is the patient prepped for excisional biopsy?

Answer 27

* Standard: * Chlorhexidine * Alcohol * saline if open wound * Supplies * Surgical drape * +/- sterile OR * Scalpel blade * Tissue forceps * Metzenbaum scssors * Needle holder * Suture * Formalin