7. Introduction to neoplasia, tumour stage and grade, tumour classification Flashcards
Define neoplasm
is an abnormal mass of tissue,
the growth of which is uncoordinated with that of normal tissues,
and that persists in the same excessive manner after the cessation of the stimulus which evoked the change“
What is an important additional component of neoplasm?
The presence of genetic alterations that alter cell growth
What is the behaviour of a benign tumour?
Slow growing
Never invade local tissues
Never mestatasise
What is the behaviour of a malignant tumour?
Variable and may be rapid
May invade surrounding tissues
May metastasise
The purpose of classification?
To provide an aid to diagnosis
to allow the accurate exchange of information
to define clinical sub groups who have different biological or clinical features
What is the tissue of origin for the prefix adeno?
Glandular epithelium
What is the tissue of origin for the prefix papillo?
Non-glandular epithelium
What is the meaning of the suffix carcinoma?
Epithelial malignancy
What are examples of benign tumour of the epithelium?
Papilloma of nose/bladder
Fibroadenoma of breast
What are examples of of malignant tumours of epithelium?
These are always carcinomas.
What is the gross appearance of a benign tumour?
Usually are well circumscribed or encapsulated
What is the gross appearance of a malignant tumour?
Often poorly defined or irregular
What is the gross appearance of a malignant tumour?
Often poorly defined or irregular
What are the microscopic appearances of a benign tumour?
Few mitoses
Usually resemble tissue of origin
Necrosis is rare
Nuclear morphology is usually normal
What are the microscopic appearances of a malignant tumour?
Often poorly defined or irregular
Variable but may be many mitoses
Variable but may only poorly resemble tissue of origin
Necrosis is common
Nuclear morphology may be variable and can be very abnormal with hyperchromasia, pleomorphism and prominent nucleoli
What does pleomorphic mean?
Usually malignant tumour
Why is classification important?
Precise classification of a neoplasm from a patient is essential for the correct and appropriate planning of treatment
What are features of a small cell carcinoma?
Numerous crowded small cells with dark nuclei and no cytoplasm
What is meant by grade?
The degree of differentiation of a tumour
Why is the degree important?
The degree to which a tumour cell resembles its presumed normal counterpart
What is the relationship between the grade of a tumour and differentiation?
the lower the grade the more differentiated
What is meant by the term stage?
Stage refers to extent of spread of a tumour
What is stage informed by?
Clinical and radiological assesment
Pathological examination of surgical speicmens
What are the benefits of using a cancer staging system?
Can determine treatment
Can determine prognosis
Can guide further investigation and follow-up
Can help evaluate response to treatment
Allows accurate communication between different treatment centres
Allows comparison of outcomes between different countries
