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'New growth' = neoplasm


Define neoplasm

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


Features of a neoplasm

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


Structure of a neoplasm

2 basic components
- parenchyma = proliferating neoplastic cells
- stroma = supportive network of connective tissue and blood vessels


Benign neoplasm

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


Malignant neoplasm

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


Routes of metastasis

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


Sites of metastasis

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


Naming a tumour

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



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



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


Pre-malignant conditions

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


Tumour grading & staging

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)


What are the effects of benign tumours?

Mechanical pressure, obstruction, ulceration, infection, hormone production


What are the effects of malignant tumours?

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


What is a paraneoplastic syndrome?

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