Disorders of growth

Question 1

Neoplasia

Answer 1

‘New growth’ = neoplasm

Question 2

Define neoplasm

Answer 2

Abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissues
A tumour is synonymous with a neoplasm

Question 3

Features of a neoplasm

Answer 3

Behaviour - is it benign or malignant
Naked eye appearance
Histological - what tissue does it resemble
Histogenesis - cell of origin
Aetiological - inheritance vs environmental factors
Functional

Question 4

Structure of a neoplasm

Answer 4

2 basic components

• parenchyma = proliferating neoplastic cells
• stroma = supportive network of connective tissue and blood vessels

Question 5

Benign neoplasm

Answer 5

Localised lesion that grows by expansion, displacing adjacent cells/tissue
Innocent, does not spread to other sites
Easy to remove

Question 6

Malignant neoplasm

Answer 6

Grows by invasion and destruction of local tissues
Aggressive behaviour, can metastasise
Primary tumour = original malignant tumour
Secondary tumour = offspring of primary

Question 7

Routes of metastasis

Answer 7

Lymphatics =
tumour may directly invade, tumour emboli may be filtered out and grown in lymph nodes eg. breast cancer
Blood =
tumour may invade blood vessels, tumour emboli filtered out y capillary beds eg. liver/lung

Question 8

Sites of metastasis

Answer 8

Lymph nodes
Liver - GIt carcinomas, bronchus, breast
Lungs - sarcomas of breast, bronchus, thyroid, kidney
Bone - carcinoma of breast, bronchus, prostate, uterus
Brain - carcinoma of bronchus
Endocrine - carcinoma of bronchus can metastasise to adrenals
Skin - malignant melanoma, clear cell carcinoma of the kidney

Question 9

Naming a tumour

Answer 9

Depends on: site, behaviour, Histogenesis
Benign epithelial tumours eg.
adenoma = arising in a gland
papilloma = finger-like projections
cystadenoma = adenomas producing cystic masses eg ovary
Malignant tumours eg.
Carcinoma = epithelial tissue
Sarcoma = stromal tissue
Mesenchymal tumours eg.
-oma if benign eg. lipoma
-sarcoma if malignant eg liposarcoma

Question 10

Leukaemia

Answer 10

Neoplastic proliferation of haematopoietic stem cells
neoplastic cells spill over into blood 
Malignant - 
>myeloid
>lymphocytic

Question 11

Lymphoma

Answer 11

Malignant proliferation of cells in lymphoid tissue
2 types:
>Hodgkin’s - mixture of cells (Reen-Sternberg cells)
>Non-Hodgkin’s

Question 12

Pre-malignant conditions

Answer 12

Lesions with an increased risk of developing invasive tumours
Can be neoplastic/non-neoplastic
eg. Non-neoplastic
- chronic inflammation eg. varicose leg ulcers can cause skin cancer
-cirrhosis of the liver can lead to hepato-cellular carcinoma
eg. Neoplastic
- intra-epithelial neoplasia

Question 13

Tumour grading & staging

Answer 13

Grading - 
an assessment of the degree of differentiation of the tumour 
correlates with how aggressive the tumour behaves
only relevant for malignant tumours
subjective, poor reproducibility, appearance can vary
Staging - 
> size of primary tumour
> lymph node spread
> any blood/bone metastasis
TNM system 
T = size of tumour (T1-T4)
N = lymph metastasis (N0-N4)
M = distant metastasis (M0-M1)

Question 14

What are the effects of benign tumours?

Answer 14

Mechanical pressure, obstruction, ulceration, infection, hormone production

Question 15

What are the effects of malignant tumours?

Answer 15

Tissue destruction, haemorrhage, secondary infection, cachexia (weakness & wasting of body due to severe chronic illness) = severe weight loss, increased metabolic rate, pain, anaemia, paraneoplastic syndromes

Question 16

What is a paraneoplastic syndrome?

Answer 16

Tumour associated syndromes in which symptoms are not directly related to spread of tumour or the production of hormones
eg. hypercalcaemia caused y bone reabsoprtion