13 Cancer Flashcards
What is a tumour?
Any kind of mass forming lesion (swelling)
What is a neoplasm?
The autonomous growth of tissue which have escaped normal constraints on cell proliferation
Neoplasma are either
- Benign
- Malignant
(cancers are malignant neoplasms)
What are benign tumours?
Tumours that remain localised
What are malignant tumours?
Tumours that invade locally/ spread to distant sites
What is metastasis?
The development of secondary malignant growths at a distance from primary site of cancer
What are hamartomas?
Localised benign overgrowths of one or more mature cell types
(architectural but not cytological abnormalities e.g. normal tissues but organisation is abnormal)
What are heterotopias?
Normal tissues being found in parts of the body where they are not normally present (wrong place)
Primary and secondary description of neoplasm
- Cell origin
2. Benign or malignant
Benign suffixes
oma
Malignant suffixes
sarcoma, carcinoma,
Exceptions to malignant suffixes
- Lymphoma
- Leukaemia
- Melanoma
- Hepatoma
- Teratoma
What are teratomas?
Tumours derived from germ cells and can contain tissue derivded from all 3 germ cell layers
Differences between benign and malignant tumours
- Invasion
- Metastasis
- Differentiation
- Growth pattern
What is invasion?
Direct extension into the adjacent connective tissue/ other structure
What distinguishes dysplasia from carcinoma?
Dysplasia - no invasion
What is metastasis?
Spread via blood vessels to other parts of the body
Which blood vessels are most susceptible to metastasis?
Veins, capillaries
- Arteries have thick, muscular walls
What is differentiation?
How much the cells of the tumour resembe the cells of the tissue they are derived from
Appearance of typical tumour cells
- Have larger nuclei
- More mitoses
- Abnormal mitoses (tripolar)
- Marked nuclear pleomorphism (variability in nuclear size and shape)
What is growth pattern?
How much does the architecture of the tumour resemble the architecture of the tissue it is derived from
(tumours have less well defined architecture)
How can tumours spread?
- Direct extension
- Haematogenous
- Lymphatic
- Transcoelomic
- Perineural
How does direct extension work?
- Associated with stromal response to tumour
- Fibroplastic proliferation (desmoplastic response), vascular proliferation (angiogenesis) and an immune response
How does haemotogenous spread work?
- Via blood vessels
- Venules and capilarries invaded (thinner walls)
- Most sarcomas metastasise first in the blood vessels
How does lymphatic spread work?
- Via lymphatics to lymph nodes
- Patter of spread dictated by normal lymphatic drainage
- Most epithelial cancers metastasise first via lymphatics
How does transcoelomic spread work?
- Via seeding of body cavities
- Pleural cavities (introthoracic cancers)
- Peritoneal cavities (intra-abdominal cancers)
How does perineural spread work?
- Via nerves
- Underappreciated route of cancer spread
How is tumour spread assessed?
Triple assessment
- Clinically (examination)
- Radiologically (imaging)
- Pathologically (frozen section)
How is tumour spread described?
TNM staging system
- T = Tumour size or extent of local invasion
- N = Number of lymph nodes involved
- M = Presence of metastases
What is grade?
How differentiated the tumour is (how different it looks from the original tissue)
- Down the microscope
- Architecture and cytology
What is stage?
How far the tumour has spread (TNM)
In terms of tumour prognosis, which is more important; stage or grade?
Stage, however high grade often indicated high stage
