GP 18 - Pathology of Neoplasia 1

Question 1

How can you tell when metaplasia has become dysplasia?

Answer 1

The following are present:

• Cellular Pleomorphisms - variation in shape and size of the cells in a tissue
• Nuclear Pleomorphisms - variation in shape and size of the nuclei in a tissue
• Disorganized arrangement of cells in a tissue

Question 2

Is dysplasia premalignant? What does that mean?

Answer 2

It is not

It means that no cellular invasion is present, just cellular transformation

Question 3

Define and differentiate aplasia, hypoplasia, and agenesis

Answer 3

Aplasia - incomplete development of an organ so that it does not attain apropriate size or function

Hypoplasia - reduced size due to incomplete development

Agenesis - complete lack of an organ

Question 4

When does dysplasia become a neoplasm?

Answer 4

When new cells begin to grow in an uncoordinated manner which exceeds that of the cells in the normal tissue. This growth must also persist after cessation of the stimulus which evoked the change.

Question 5

How are neoplasms classified?

Answer 5

By the type of neoplastic cell (tissue of origin) and the nature of the tumor (benign or malignant)

Question 6

Bescribe the basics of benign tumor nomenclature.

Answer 6

In general, benign tumors have the suffix “-oma” following the neoplastic cell type. Some are also named by architectural patterns. Exceptions are melanoma and lymphoma, which are malignant

Question 7

Describe the basics of malignant tumor nomenclature.

Answer 7

Very similar to benign tumor nomenclature. However:

• If the tumor is of mesenchymal origin, the suffix will be “-sarcoma” instead of just “-oma”
• If the tumor is of epithelial origin, the suffix will be “-carcinoma” instead of just “-oma”
• If the tumor is of more than one cell type, it is called a teratoma

Exceptions are melanoma (coming from melanocytes) and lymphoma (coming from lymphocytes)

Question 8

Fill in the table

Answer 8

Question 9

What is a choristoma?

Answer 9

Normal tissue growth occurring in an abnormal location (ectopic)

Question 10

What is a Hamartoma?

Answer 10

Disorganized normal tissue

Question 11

Answer 11

Question 12

What is a blastoma? Give the three major examples of this type of cancer.

Answer 12

A tumor thought to arise in embryonic tissue (mostly occur in children)

• Retinoblastoma (retina)
• Hepatoblastoma (liver)
• Neuroblastoma (neural origin)

Question 13

Describe what differentiation and anaplasia are in relation to neoplasms. How can these characteristics be used to tell if a tumor is benign or malignant?

Answer 13

• Differentiation - the extent to which tumor cells resemble their normal counterparts (morphologically and functionally)
• Anaplasia - the lack of differentiation

All benign tumors are well differentiated, however, not all well differentiated tumors are benign.

The lack of various degrees of differentiation is characteristic of malignancy

Question 14

What are common microscopic features of anaplastic malignant cells?

Answer 14

• Variable cell size and shape
• Variable nuclear size and shape
• Increased nuclear cytoplasmic ratio
• Hyperchromatic nuclei (increased DNA)
• Increased mitosis and abnormal mitosis
• Tumour giant cell

Question 15

In general, how do the growth rates of benign and malignant tumors compare? What are some exceptions and confounding factors?

Answer 15

• Typically benign tumors are slow growing while malignant tumors are fast growing
• Blood supply (the more the faster) and differentiation (the less the faster) effect tumor growth

Exception - growth of leiomyoma (benign) during pregnancy is fast

Question 16

Aside from metastasis, what is perhaps the most reliable feature to assess when trying to determine if a tumor is malignant?

Answer 16

Invasion

Benign tumors do not invade, they grow by expansion

Malignant tumors invade and destroy the tissue.

Question 17

What is carcinoma in situ? What else can it be called?

Answer 17

A carcinoma that has not penetrated the basement membrane. AKA - sever dysplasia or intraepithelial neoplasia

Question 18

What are the metastatic pathways?

Answer 18

• Seeding via body cavities - peritoneal cavity is most common (from ovarian carcinoma), followed by pericardial, pleural, and subarachnoid
• Lymphatic Spread - most common for carcinomas (follow natural drainage)
• Hematogenous Spread - most common for sarcoma. Liver and lungs are frequent sites

Question 19

What is this?

Answer 19

Invasive squamous cell carcinoma

Question 20

What is this?

Answer 20

Dysplastic epithelium

Question 21

What is this?

Answer 21

Uterine leiomyoma

Question 22

What is this?

Answer 22

Adrenal adenoma

Question 23

What is this?

Answer 23

Melanoma