Inflammations & Tumors: Acute, Chronic, & Neoplastic Processes

Question 1

What is the primary aim of acute inflammation?

Answer 1

Acute inflammation is a host protective response that removes injurious agents, limits tissue damage, and initiates repair​.

Question 2

What are the two major phases of acute inflammation?

Answer 2

1) Vascular phase – Changes in blood vessels (vasodilation, increased permeability).

2) Cellular phase – Recruitment of leukocytes (mainly neutrophils) to the site of injury​

Question 3

What are the five classic signs of inflammation?

Answer 3

1) Rubor (redness) – Due to increased blood flow.

2) Calor (heat) – Due to hyperemia.

3) Tumor (swelling) – Due to increased vascular permeability.

4) Dolor (pain) – Due to release of chemical mediators.

5) Functio laesa (loss of function) – Due to tissue damage

Question 4

What are the main mediators of acute inflammation?

Answer 4

Histamine, prostaglandins, leukotrienes, cytokines (IL-1, IL-6, TNF-α), complement proteins, and platelet-activating factor

Question 5

How does chronic inflammation differ from acute inflammation?

Answer 5

• Chronic inflammation is prolonged, involves macrophages and lymphocytes, and leads to fibrosis and tissue destruction.
• Acute inflammation is short-term, mainly involving neutrophils​

Question 6

What is the acute-phase response?

Answer 6

A systemic reaction to inflammation, characterized by fever, leukocytosis, increased acute-phase proteins (e.g., CRP, fibrinogen), and metabolic changes​.

Question 7

What is a neoplasm?

Answer 7

An abnormal mass of tissue that grows uncontrollably, often bypassing normal regulatory mechanisms​.

Question 8

What is the key difference between benign and malignant tumors?

Answer 8

• Benign tumors – Well-differentiated, slow-growing, non-invasive, and do not metastasize.
• Malignant tumors – Poorly differentiated, rapid-growing, invasive, and capable of metastasis

Question 9

Name at least two characteristics distinguishing benign from malignant tumors.

Answer 9

1) Growth rate – Malignant tumors grow faster.

2) Invasiveness – Malignant tumors infiltrate surrounding tissues.

3) Metastasis – Only malignant tumors spread distantly

Question 10

What is an adenoma?

Answer 10

A benign tumor arising from glandular epithelial tissue.

Question 11

What are the steps of metastasis?

Answer 11

1) Local invasion – Tumor cells break through basement membrane.

2) Intravasation – Tumor cells enter the bloodstream or lymphatics.

3) Circulation – Tumor cells survive in circulation using platelet cloaking.

4) Extravasation – Tumor cells exit blood vessels into a distant tissue.

5) Colonization – Growth in a new organ, forming secondary tumors

Question 12

What are the key routes of tumor spread?

Answer 12

1) Direct extension – Local tissue invasion.

2) Lymphatic spread – Common for carcinomas.

3) Hematogenous spread – Common for sarcomas, often to lungs/liver​.

Question 13

What is an oncogene?

Answer 13

A gene that, when mutated or overexpressed, drives uncontrolled cell growth (e.g., RAS, MYC)

Question 14

What is a tumor suppressor gene?

Answer 14

A gene that normally prevents uncontrolled cell division (e.g., TP53, RB1). When inactivated, cancer develops.

Question 15

What is the function of p53?

Answer 15

p53 is a tumor suppressor gene that induces apoptosis in damaged cells to prevent cancer. Mutations in TP53 are found in many human cancers​

Question 16

What is the role of RAS in cancer?

Answer 16

RAS is an oncogene that promotes cell proliferation. Mutations in RAS lead to continuous cell signaling and uncontrolled growth​.