Chapter 4 - Interpreting the Complex Epithelium

Question 1

What general features of the epithelium should be appreciated at low power?

Answer 1

Type of epithelium

Architecture & orderliness

Keratinization

Thickness

Color

Question 2

What high-power epithelial features should be evaluated for dysplasia & carcinoma in situ?

Answer 2

Architectural orderliness

Mitotic figures

Dyskeratotic cells

Invasion

Nucleoli

N:C ratios

Question 3

Define:

Hyperkeratosis

Orthokeratosis

Parakeratosis

Answer 3

Hyperkeratosis: Too much keratin, sitting in a thick layer atop the epithelium

Orthokeratosis: Normal keratin, with a basket weave pattern. Anucleate!

Parakeratosis: Retention of small pyknotic nuclei in the surface keratin

Question 4

Define:

Papilloma

Inverted papilloma

Answer 4

Papilloma: Exophytic growth of finger-like, arborizing projection, with a fibrovascular core.

Inverted papilloma: Endophytic growth of benign squamous epithelium. Nests are surrounded by stroma, with no fibrovascular cores.

Question 5

Define:

Pseudoepitheliomatous hyperplasia

Verrucous

Answer 5

Pseudoepitheliomatous hyperplasia: Bening reactive condition that simulates invasive squamous cell carcinoma.

Verrucous: Exophytic with prominent hyperkeratosis. “Church-spire” or “cauliflower” morphology.

Question 6

Distinguish between cervical LSIL and HSIL.

Answer 6

LSIL: Koilocytic changes with basal layer disorganization and mitoses in the bottom 1/3.

HSIL: Mitosis above the bottom third; undifferentiated cells occupying half or more of hte epithelium. High N/C ratios.

Question 7

Distinguish between the flat and papillary urothelial carcinomas.

Answer 7

Flat: Dysplasia >> CIS >> Invasive carcinoma

Papillary: Must be designated low-grade or high-grade, invasive or non-invasive. No “dysplasia” here.

Question 8

How is the squamous mucosa of the oropharynx different than the cervix?

Answer 8

In the oropharynx and larynx, dysplasia tends to result in keratinization. “Severe keratinizing dysplasia” is more insidious as it can become invasive without being full-thickness.

Question 9

What are Schneiderian papillomas? Describe their morphology.

Answer 9

Fungiform or inverted masses lined with nonkeratinizing epithelium (sometimes ciliated or mucous). Inflamed with only mild atypia. Consider invasive lesions!

Question 10

How does squamous dysplasia arise from respiratory epithelium?

Answer 10

When irritated, respiratory epithelium undergoes squamous metaplasia. Dysplasia may then arise there.

Question 11

Why is squamous dysplasia rarely seen on biopsy?

Answer 11

It is asymptomatic!

Question 12

Answer 12

Normal urothelium, with polarization.

Arrow: Umbrella cells

Question 13

Answer 13

Dyskeratotic epithelial cells

Question 14

Answer 14

Top (A/B): Reactive, benign epithelium

Bottom (C/D): Dysplastic epithelium

Question 15

Answer 15

Invasive squamous cell carcinoma

Arrow: Deep aberrant keratinization

Question 16

Answer 16

Papilloma

Arrow: Fibrovascular core surrounded by squamous epithelium.

Question 17

Answer 17

Pseudoepitheliomatous hyperplasia

Arrow: Strands of epithelium pulled into the dermis or LP without keratinization or invasion.

Question 18

Answer 18

Verrucous wart

Arrow: Exophytic spires with hyperkeratosis & parakeratosis

Question 19

Answer 19

Top: Viral/koilocytic atypia with perinuclear halos (arrow) and binucleate cells (arrowhead)

Bottom: Normal glycogenated epithelium, also with perinuclear halos, but small & pyknotic nuclei.

Question 20

Answer 20

HSIL, with an abrupt transition to normal mucosa (arrow).

Question 21

Answer 21

Squamous dysplasia in the mouth.

Arrow: Dysplastic cells with high N:C ratio
Arrowhead: Hyperkeratosis, clinically appearing as a white plaque
Inset: Prominent nucleoli (not seen in cervical dysplasia)

Question 22

Answer 22

Schneiderian papilloma

1. Goblet cells (respiratory epithelium)
2. Fibrovascular cores