tumour classification

Question 1

outline the difference between the terms neoplasm and tumour

Answer 1

tumour = anything that causes an abnormal swelling, for example, inflammation, neoplasm, hypertrophy or hypotrophy

neoplasm = a localised abnormality from an abnormal growth of cells which persists after the initiating stimulus has been removed

Question 2

define neoplasm

Answer 2

A lesion (localised abnormality) resulting from the autonomous or relatively autonomous abnormal growth of cells which persists after the initiating stimulus has been removed.

• it is persistent and no longer needs an initiating event to grow

Question 3

what are the 2 main structural components of a neoplasm?

Answer 3

• neoplastic cel
• stroma

Question 4

what are the 3 behavioural classifications of neoplasm?

Answer 4

Benign
Borderline
Malignant

however its pretty much a scale and not always a set catagory

Question 5

What is the role of the neoplastic cell in a neoplasm?

Answer 5

• known as the tumour cellswhich drives the neoplasms growth
• Makes up the proliferating abnormal cells
• Determines the biological behaviour and tumour type (e.g., carcinoma or sarcoma).

Question 6

What is the role of the stroma in a neoplasm?

Answer 6

• non-cancerous supportive tissue that surrounds and interacts with the neoplastic cells
• Provides structural support and supplies nutrients, oxygen, and growth signals.
• Includes connective tissue, blood vessels, and inflammatory cells.

Question 7

what type of cells are neoplastic cells derived from and what determines their growth pattern?

Answer 7

• Derive from nucleated cells
• Usually monoclonal
• Growth pattern and synthetic activity related to parent cell

Question 8

which characteristics do we use to classify neoplasms?

Answer 8

Behavioural - Benign/Malignant
Histogenetic - Cell of origin
degree of classification - how much they resemble normal tissue

Question 9

outline the characteristics of malignant neoplasms?

Answer 9

• Invasive
• Metastases - process of cancer cells spreading from origin and invading
• Rapid growth rate
• Variable resemblance to normal tissue
• Poorly defined or irregular border on histology slides compared to normal tissue

Question 10

what microscopic structural characteristics do malignant neoplasms have?

Answer 10

• Hyperchromatic nuclei
• Pleomorphic nuclei (variation in size, shape and structure)
• Increased mitotic activity
• Necrosis and ulceration common
• Growth on mucosal surfaces and skin often endophytic

Question 11

why are benign neoplasms still a potential cause for concern?

Answer 11

• Pressure on adjacent structures
• Obstruct flow
• Produce hormones
• Transform to malignant neoplasm
• Anxiety

Question 12

what are the characteristics of benign neoplasms?

Answer 12

• Localised, non-invasive
• Slow growth rate
• Low mitotic activity
• Close resemblance to normal tissue
• Circumscribed or encapsulated
• Nuclear morphometry often normal
• Necrosis is rare
• Ulceration is rare
• Growth on mucosal surfaces usually exophytic (projecting outwards, eg moles)

Question 13

define histogenesis.

Answer 13

The specific cell of origin of a neoplasm

Question 14

when would the term adenoma be used to describe a neoplasm?

Answer 14

• Benign neoplasm of glandular or secretory epithelium
• Prefix with cell type of origin, e.g. colonic adenoma, thyroid adenoma

Question 15

what are the 2 names to describe benign epithelial neoplasms?

Answer 15

• adenoma
• papilloma

Question 16

when would the term papilloma be used to describe a neoplasm?

Answer 16

• Benign neoplasm of non-glandular non-secretory epithelium
• Prefix with cell type of origin, e.g. squamous cell papilloma

Question 17

what is the term given to malignant epithelial cancer?

Answer 17

• carcinoma

Question 18

what is the term given to carcinomas of glandular epithelium?

Answer 18

adenocarcinomas

Question 19

what are the terms given to benign connective tissue neoplasms, adipocytes, cartilage, bone and vascular, striated muscle, smooth muscle and nerves and how would these names differ if the cancer was malignant?

Answer 19

Lipoma: adipocytes
Chondroma: cartilage
Osteoma: bone
Angioma: vascular
Rhabdomyoma: striated muscle
Leiomyoma: smooth muscle
Neuroma: nerves

if cancer was malignant it would have “sarcoma” instead of “oma”

Question 20

define anaplastic

Answer 20

Where cell type of origin cannot be determined, the neoplasm is said to be anaplastic

Question 21

exceptions to the rule

Answer 21

• Not all ‘-omas’ are neoplasms
  e.g. granuloma, mycetoma, tuberculoma
• Not all malignant neoplasms are carcinomas or sarcomas, e.g.:
  Melanoma: malignant neoplasm of melanocytes
  Mesothelioma: malignant neoplasm of mesothelial cells
  Lymphoma: malignant neoplasm of lymphoid cells
• some neoplasms are named after someone eg burkitt lymphoma
• embryonal neoplasms
• mixed neoplasms