neoplasia Flashcards
suffix -oma
tumour
neoplasm
a new and abnormal growth of a tissue - tumour
persists even after stimuli removed
how are tumours classified
by their
clinical behaviour - benign or malignant
histogenesis - tissue of origin
metastasis
development of secondary malignant growths at a distance from the primary site
benign vs maligant
growth patterns
benign - all parts expand at same rate and time , encapsulated therefore localised
malignant - no capsule therefore spread via infiltration/ invasion. potential for metastasis
benign vs malignant
growth rate
benign - slow
malignant - fast
benign vs malignant
histology
benign - cells resemble tissue of origin, few dividing cells
malignant - variable resemblance to origin tissue, cells change shape/ size (pleomorphism), manny mitotic figures
pleomorphism
more than one form
benign vs malignant
clinical effects
benign - small effects, swelling causes pressure on other structures which may cause excess hormone release
malignant - pressure, destruction, invasion, requires surgery/ chemotherapy to remove
carcinoma
malignancy of epithelium
name of benign and malignant tumour in glandular epithelium e.g the salivary glands
benign - adenoma
malignant - adenocarcinoma
name of benign and malignant tumour in squamous epithelium
benign - papilloma
malignant - squamous cell carcinoma
suffix for malignant tumours in connective tissues
sarcoma e.g osteosarcoma
environmental carcinogens
viruses (oncogenic viruses)
chemical agents
physical agents
chemical agent examples
smoking, diet, drugs, alcohol, asbestos
stages of chemical carcinogenesis
1 - initiation - cell mutates and passes mutation onto daughter cells but remains stable
2 - promotion - exposure to another carcinogen makes cell divide faster and become genetically unstable passing these effects on
latent period
time between initiation and promotion - could be years
pro-carcinogen
substance that is transformed into a carcinogen by metabolism
co-carcinogen
carcinogens that need to act together
physical carcinogenesis
ionising radiation
damages DNA causing mutations
has greatest effects in tissues that rapidly renew e.g the epidermis
examples of oncogenic viruses
HPV - types 16 and18
HEP B/C
top causes of oral cancer
smoking = 1
alcohol (pro-carcinogen and often combined with smoking)
bad oral hygiene
viruses eg HPV
is sunlight a cause of oral cancers
no
leukoplakia
white patch that cant be rubbed off or attributed to any other cause - could be malignant biopsy required
dysplasia
changes in cells appearance/ size
could be malignant
