Characteristics of Tumours Flashcards
What is the WHO definition of cancer?
cancer is the uncontrolled growth of cells, which can invade and spread to distant sites of the body
Define tumour
(=neoplasm) lesion resulting from the autonomous growth or relatively autonomous growth of cells that persists in the absence of the initiating stimulus
What is histiogenesis?
the differentiation of cells into specialised tissues and organs during growth from undifferentiated cells
What are the histiogenic classifications of the following tumour by cell type: epithelial cells, connective tissues, lymphoid/haematopoietic organs?
eptithelial cells - carcinomas
connective tissues - sarcomas
lymphoid/haematopoietic organs - lymphomas/leukaemias
Define differntiation
the extent that neoplastic cells resemble the corresponding normal parenchymal cells, morphologically and functionally
Are benign or malignant tumours usually better differentiated?
benign
What are anaplastic neoplasms?
comprised of poorly-differntiated cells (telltale sign of malignancy)
What is pleomorphism?
variation is size and shape of cells
What abnormal nuclear changes might you expect to see in a poorly differentiated neoplasm?
- increased nuclei to cytoplasm ratio
- variable nuclear shape
- chromatin distributed poorly (clumped along cell membrane)
- hyperchromatism
What does loss of polarity describe in poorly differntiated cells?
-orientation of cells disturbed and growth in disorganised
Describe grade 1,2 and 3 neoplasms?
grade 1: well differentiated
grade 2: moderately differentiated
grade 3: poorly differentiated
What is stage a measure of?
prognastic/therapeutic decisions
Define metastasis
spread of a tumour to sites physically discontinuous with the primary tumour
What are the 3 main pathways of metastases?
- direct seeding
- lymphatic spread
- haematogenous spread
Define sentinel nodes
the first node in a regional lymphatic basin that receives lymph flow from the primary tumour
