Lecture 21 11/21/24

Question 1

How does cytology compare to histopathology?

Answer 1

cytology:
-evaluation of individual cells
-sampling of cells spread directly on glass slide
-specimens can be collected and slides prepared in most clinics
-evaluated by clinical pathologists
histo:
-evaluation of tissue sections
-sections of formalin-fixed tissue
-tissue collected by veterinarian but processed by histo lab
-evaluated by anatomic pathologists

Question 2

What are the indications for cytology?

Answer 2

-characterize a detected abnormality
-cancer staging

Question 3

What are the pros of cytology?

Answer 3

-quick and easy
-relatively safe to collect
-quick results
-often less expensive
-better fine detail of individual cells and infectious agents

Question 4

What are the cons of cytology?

Answer 4

-no tissue architecture
-only sampling a very small area

Question 5

What are the pros of histopath?

Answer 5

-evaluation of tissue architecture
-larger area is sampled

Question 6

What are the cons of histopath?

Answer 6

-longer turnaround time
-usually requires anesthesia and more equipment
-more expensive
-more risk of complications
-less cellular detail

Question 7

What are the sampling techniques for soft tissue cytology?

Answer 7

fine needle techniques:
-pin cushion/stab technique
-fine needle aspirate
exfoliative:
-impression smears

Question 8

Why is formalin bad for cytology?

Answer 8

formalin drastically alters the staining properties of cells and renders the cytology non-diagnostic

Question 9

What are the steps of cytology slide evaluation?

Answer 9

-evaluate slide quality
-identify types of cells present, including inflammatory and non-inflammatory cells

Question 10

What are the characteristics of a high quality slide?

Answer 10

having all of the following:
-adequate cellularity
-intact cells
-well-spread monolayer of cells

Question 11

What are the causes of neutrophilic and/or macrophagic inflammation?

Answer 11

-bacteria
-fungus
-some parasites
-foreign body
-necrosis
-immune-mediated disease

Question 12

What are the causes of eosinophilic inflammation?

Answer 12

-parasites
-arthropod bites/stings
-hypersensitivities
-neoplasia

Question 13

What are the causes of small lymphocytes on cytology slides?

Answer 13

-immune stimulation
-tumor-associated lymphocytes (non-lymphoid tumors)
-small cell lymphoma

Question 14

Which aspects of cells should be evaluated during cytology?

Answer 14

-whether the cell type is normally expected at the site
-whether the cells are cytologically atypical
-how the cells correlate to other clinical findings

Question 15

What are the cytologic features of epithelial cells?

Answer 15

-exfoliate in clusters
-variable shape depending on type of epithelium

Question 16

What are the cytologic features of mesenchymal cells?

Answer 16

-exfoliate individually
-spindled, fusiform, irregular to stellate shape

Question 17

What are the cytologic features of round cells?

Answer 17

-exfoliate individually
-round cell shape
-can often diagnose with confidence on cytology

Question 18

What is a non-neoplastic example of round cells on cytology?

Answer 18

inflammatory cells

Question 19

What are examples of round cell tumors?

Answer 19

-lymphoma
-plasma cell tumors
-mast cell tumors
-cutaneous histiocytoma
-histiocytic sarcoma
-transmissible venereal tumor

Question 20

What are the characteristics of benign vs malignant classification?

Answer 20

-histopath. better for determination
-takes anatomic location, other clinical information, and typical biologic behavior into account
-cytologic features are more commonly noted in malignant lesions

Question 21

What are the cytologic criteria of malignancy?

Answer 21

-pleomorphism/anisocytosis/anisokaryosis
-macrocytosis
-multinucleation with intracellular anisokaryosis
-numerous nucleoli
-increased nuclear size
-abnormal mitotic figures

Question 22

What are the characteristics of inflammation and epithelial dysplasia?

Answer 22

-inflammation or irritation can cause epithelial cells to appear morphologically abnormal
-difficult to distinguish from neoplasia

Question 23

What are the characteristics of inflammation and reactive fibroblasts?

Answer 23

-fibroblasts can proliferate in response to inflammation and appear morphologically abnormal
-difficult to distinguish from neoplasia

Question 24

What is important about hyperplastic epithelium?

Answer 24

can look similar to normal tissue or to well-differentiated epithelial neoplasia

Question 25

What is important about cytologic atypia?

Answer 25

does not correlate to biologic behavior in all tumors

Question 26

What can be done when sampling to ensure focal pathology is not missed?

Answer 26

-sample several different areas of a lesion
-sample more solid areas than fluid-filled areas