eBook Chapter 7 - Pathology of Cancer Flashcards
Why is cancer pathology important?
- it explains how cancers present clinically
- histopahtoligcal assesmnet importnat for diagnosis, prognosis and threaten
- pathology is a bridge between basic science and clinical medicine
In what four ways can we classify tumours/
- behavioural
- histogenetic
- histological
- functional
Describe how we classify tumours based on their behaviour
- can be classified as benign or malignant according to their behaviour
- the essential difference is local invasion into surrounding tissue and spread to distant sites - metasiss
- We use TNM staging
What is meant by the term staging?
- used to describe the extent of spread of a malignant neoplasm
- TNM is a commonly used generic staging tool
What is the staging tool used for colon cancer?
Dukes
Why is staging important?
- predicting prognosis and thus also has implications for determining therapeutic options (e.g. local resection vs chemotherapy/radiotherapy)
Describe how we classify tumours histogenetically
- classification of neoplasms according to tissue of origin (e.g. eptihaliel, mesenchymal)
- the term differentiation is used to describe the degree to which a neoplasm histologically resembles its tissue of origin
- benign tumours are always well-differnetiated
- grading has implications for prognosis and treatment
What is meant by grading?
- describes the degree of differentiation
1 = well differentiated
2 = moderately differentiated
3 = poorly differentiated
What is meant by the term anaplastic?
- some malignant tumours are so poorly-differentiated that it is impossible to determine their histiogeneis s
How can we classify tumours histologically?
- many tumours can be further classified according to special histological characteristics e.g. thyroid adenocarcinoma
- papillary, follicular, anaplastic
How can we classify tumours functionally?
- some may be classified according to a substance or substances produced
- especially endocrine tumours, which secrete functionally active hormones
- e.g. pancreatic islet cell tumours, pituitary tumours
What are teratomas?
Where do they usually occur?
- tumours derived from embryonic germ cells which have the capacity to form representatives of all 3 germ cell layers
- usually occur in ovary = benign, testis = malignant, midline structures = behaviour variable (retroperiotonem, mediastinum)
What are embryonic tumours?
- represent neoplastic transformation occurring in the developing organ, they are derived form multi portent embryonic blast cells and are give the suffix blastoma
- the majority present at or soon after both , they are the commenest cause of neopplasmsa in childhood and are highly malignant
What are hamartomas?
- not genuine neoplasm but tumour-like malformations
- many are present at birth and stop growing when the host stops growing
- examples include pigmented skin naevi and haemangiomas
What are the 3 specimens obtained for pathological assessment? Give examples
- biopsies
- endoscopic, needle, punch - cytology specimens
- smear, endoscopic brushings, body fluids, FNA - surgical resection specimens
Describe the macroscopic assessment of tumour resected specimens
- size
- shape (well-circumscribed or irregular)
- extend of local spread
- proximity to surgical resections margins
- identification of lymph nodes (important for staging)
- other macroscopic features were relevant e..g colour, haemorrhage, necrosis
What are features are assessed microscopically for tumour resected specimens?
- historical type e.g. glandular, squamous
- degree of differentiation (grading)
- frequency of mitosis
- local invasion
