Part 2 197

Question 1

Components of benign and malignant tumors

Answer 1

1. Parenchyma

2. Stroma

Question 2

Parenchyma

• Definition

Answer 2

neoplastic component that determines biological behavior

Question 3

Stroma

a. Definition
b. Desmoplasia

Answer 3

a. nonneoplastic supportive tissue

b. Most infiltrating carcinomas induce production of a dense, fibrous stroma

Question 4

Benign tumors

• Definition

Answer 4

usually well differentiated (resemble parent tissue)

Question 5

Malignant tumors

low grade

Answer 5

Well-differentiated or low grade cancer

(1) Cancer cells resemble parent tissue

Question 6

Malignant tumors
low grade
Examples

Answer 6

• parenchyma shows keratin pearls (characteristic of squamous tissue)
• glandular lumens with secretions (characteristic of normal gland lumens with secretions)

Question 7

Malignant tumors

High Grade

Answer 7

Poorly differentiated, high grade, or anaplastic

• No differentiating features (e.g., no glands, no keratin staining material)

Question 8

Malignant tumors

Intermediate grade

Answer 8

Features are between a low- and high-grade cancer
e.g., occasional gland-like
structures are seen, or areas that look like keratin are present, whereas the rest of the
tumor has no differentiation

Question 9

Organelles of malignant cells

Answer 9

a. Fewer mitochondria
b. Less prominent rough endoplasmic reticulum (RER)
c. Loss of cell-to-cell adhesion molecules (cadherins)

Question 10

Cadherins are

Answer 10

a group of calcium-dependent transmembrane proteins that play an
important role in cell-to-cell adhesion.

Question 11

Malignant cell nuclear features

Answer 11

a. Nucleus is larger, has irregular borders, and has more chromatin (hyperchromatic)
b. Nucleolus is larger and has irregular borders
c. Mitoses have normal and atypical mitotic spindles