P4 +5 - Disorders of growth and neoplasia 2/3 Flashcards
What are the 2 classifications of tumours?
- Behaviour
2. Histogenesis
what are the 2 behaviours of tumours?
Benign v Malignant
what is the growth patten of benign tumours?
Expand and Remain localised
Typically well-circumscribed
Often encapsulated
what is the growth rate of benign tumours?
slower
what are the clinical effects of benign tumours?
local pressure effects: hormone secretion
what is the treatment for benign tumours?
local excision
what is the histology of benign tumours?
Resembles tissue of origin
what is the nuclei of benign tumours?
small, regular, uniform
what are the mitoses of benign tumours?
few, normal
what is the growth patten of malignant tumours?
Infiltrate locally, metastasize (spread to distant sites)
what is the growth rate of malignant tumours?
Faster
what is the clinical effects of malignant tumours?
Local pressure and destruction,
Inappropriate hormone secretion
Distant metastases
what is the treatment for malignant tumours?
Excision and additional therapy if metastases
what is the histology of malignant tumours?
Variable, many differ from tissue of origin
what is the nuclei of malignant tumours?
Larger, pleomorphic
what are the mitoses of malignant tumours?
Numerous, including abnormal forms
How can tumours be further classified?
- the cell type they resemble, ie their differentiation
- Most tumours resemble to some extent the tissue from which they arise
what is the benign tumour of covering epithelia?
papilloma
what is the malignant tumour of covering epithelia?
Carcinoma
what is the benign tumour of Glandular epithelia?
Adenoma
what is the malignant tumour of glandular epithelia?
adenocarcinoma
What are the benign tumours of smooth muscle, skeletal. muscle, bone forming, cartilage fibrous, blood vessels , adipose?
SM- leiomyoma Skeletale muscle-Rhabdomyoma BF- osteoma C- Chondroma F- Fibroma BV- (Haem)angioma A- Lipoma
What are the malignant tumours of smooth muscle, skeletal. muscle, bone forming, cartilage fibrous, blood vessels , adipose?
SM- leiomyosarcoma Skeletale muscle-Rhabdomyosarcoma BF- osteosarcoma C- Chondrosarcoma F- Fibrosarcoma BV- Angiosarcoma A- Liposarcoma
what may some highly malignant tumours be?
undifferentiated ie do not show any definite form of differentiation
Why does tumour type matter?
- Different tumour types behave in different ways
- Different benign tumours can behave differently
- Not all malignant tumours are equally malignant
What is the prognosis?
- Prediction of the probable course and outcome of disease
- Appropriate treatment and estimate survival
What does cancer prognosis include?
- Tumour Type
- Tumour Grade (Histology)
- Tumour Stage (Histology, Clinical, Radiological)
- Other Parameters (Patient ,Tumour)
What does knowing patterns of spread of tumour types aid?
diagnosis, staging and treatment
what is important anatomical knowledge to know for tumours?
Sentinal lymph node biopsy
what does tumour type influence?
How patients are investigated, treated and monitored
Describe aggressive versus indolent tumours.
- May need to treat before tissue diagnosis
- Risk:benefit to consider at all times
- Aggressive therapy may be necessary and risks are justifiable
- Sometimes appropriate to avoid early active treatment
what is tumour grade?
-The degree of malignancy
- Usually correlates well with patient survival
(tumour grade is how well differentiate the tumour is)
Describe tumour grade.
- A histological assessment
- How well differentiated the tumour cells are
- Well differentiated tumours tend to have a better prognosis
what is “Oral cancer” Squamous cell carcinoma graded by?
degree of differentiation
what are well- differentiated squamous cell carcinoma?
very obviously squamous with ‘prickles’ and keratinization
what are poorly differentiated squamous cell carcinoma?
may be difficult to identify tumour cells as epithelial
what is the tumour stage?
how advanced the tumour is
Describe tumour stage?
A clinical, radiological and histological assessment:
- Clinical examination
- Radiology
- Other Investigations
what is used to identify tumour stage?
TNM system
T= greatest diameter of tumour, structures invaded N= lymph node status M= metastasis
Eg pT2N1 (pathology)
what does tumour stage correlate with?
outcome in most tumour types
what does high tumour stage mean?
poorer prognosis
what are key elements in cancer development?
-Tumour growth: >Replication >Escape from senescence >Evasion of apoptosis >Limitless replicative potential -Angiogenesis -Invasion and metastasis
What is angiogenesis?
formation of new blood cells to support the needs of the tumour
what are the components of a neoplasm?
-Neoplastic cells
-Blood Vessels
-Inflammatory cells:
>Macrophages
>Lymphocytes
>Polymorphs
-Fibroblasts
-Stroma
what are all neoplastic cells in a lesion derived from?
single common ancestor
-neoplastic cells are monoclonal
what is invasive malignancy?
invades the underlying connective tissue
Describe the stages of tumour growth?
- normal
- intial event
- mild dysplasia
- severe dysplasia
- invasive malignancy
What type of process is dysplasia?
a pre-malignant process
what is a good example of dysplasia?
epithelia:
- squamous
- glandular
Describe dysplasia (pre-invasive).
-Cells show abnormal features that are also seen in cancer cells ….
-They are NOT invasive.
-Different degrees of dysplasia:
>Mild
>Moderate
>Severe / carcinoma in situ
- The more severe forms have a significant risk of progressing to invasive malignancy.
Describe benign neoplasms.
- Benign tumours can progress to become malignant
- Evidence for multi-step theory of carcinogenesis
- Now reflected in molecular studies of cancer development
What is involved in the development of a cancer?
invasive growth, desmoplasia, angiogenesis and metastasis
Describe what is involved in invasive growth.
- receptors for connective tissues e.g laminin
- adhesion molecules
- altered cell division and apoptosis -pressure of growth
- proteolytic enzymes e.g collagenases Cathepsin
Describe what happens in invasive growth.
-Migration of cells that have detached from the primary tumour mass
-Single cells – >Mesenchymal migration (Proteolysis / traction) >Amoeboid movement (pseudopodiaPropulsion / Utilise defects)
-Groups of cells
>Requires cell-cell adhesion and communication
>Predominates in well differentiated carcinomas
>Inner cells protected from immunological assault
>High levels of autocrine pro-migratory factors and of proteolytic enzymes.
>Heterogeneous sets of cells invade together
Describe the tumour stroma -desmoplasia.
- Variable – scanty to abundant.
- Fibro-connective tissues associated with malignant tumours.
- Stimulated by invasive disease
- Firm, craggy feel of cancer
What happens in angiogenesis?
-Formation of new blood vessels
-Under tight physiological control
-Control is lost in tumours – the angiogenic switch.
-Vessels formed are abnormal
-New blood cells formed by outgrowth of endothelial cells from post capillary venules into tumour mass
-Stimlulus is increased production of factors by tumour cells:
>VEGF, FGF, angiogenin
>Inhibition of angiogenesis potential anticancer therapy area
What is angiogenesis a pre-requisite for?
tumour progression
how are tumours vascularised?
to a different extent
what do tumours require?
less oxygen and metabolites than normal cells
what does the density of tumour microvasculature need not correlate with?
prognosis
what are metastasis?
- Tumour implants that are discontinuous with the primary lesion.
- “Secondaries”
- Sinister event.
- Non-random
- Practical implications
Name some common sites of metastatic disease.
- Regional lymph nodes
- Liver
- Lung
- Bone
- Brain
- Skin
what are unusual sites of metastatic disease?
think of renal cancer, thyroid cancer, melanoma
What spreads through lymphatic metastasis?
carcinoma
what spreads haematogenous ?
sarcoma
what is the route of metastasis across body cavities?
- serous cavities
- meninges/ventricles /spinal canal
what accounts for common metastatic profiles?
circulatory patterns
what is effective at arresting circulating cancer cells?
lung and liver
Describe the delivery and growth of cancer cells.
Delivery of cancer cells to a potential metastatic site is primarily mechanical – but the growth of metastatic deposits is dependent upon compatability with the “soil”.
what are neck nodes divided into?
1-5
what are the nodes in 1?
Submental and submandibular
what are 2,3 , 4?
cervical chain - associated with sternocleidomastoid
what is 5?
posterior triangle
what stages do most oral cancers include?
1-4
