Tumour Pathology Flashcards
classification of tumours depends on …
tissue of origin
benign or malignant
epithelial tumours
glandular- benign = adenoma
malignant = adeno-carcinoma
squamous - benign = squamous papilloma
malignant = squamous carcinoma
bone tumours
benign = osteoma malignant = osteosarcoma
fat tumours
benign = lipoma malignant = liposarcoma
fibrous tissue tumours
benign = fibroma malignant = fibrosarcoma
white blood cell tumour
malignant = leukaemia
lymphoid tissue tumour
malignant = lymphoma
germ cell tumours
teratomas
ovarian = benign testes = malignant
benign tumour features
non-invasive growth pattern usually encapsulated no evidence of invasion no metastases cells similar to normal and function similar to normal tissue rarely cause death
malignant tumour features
invasive growth patterns no capsule, or capsule breached by tumour cells cells abnormal poorly differentiated loss of normal function often evidence of spread often cause death
properties of cancer cells
altered genetics - loss of tumour-suppressor genes, gain of function of oncogenes
altered cellular function - tumour related proteins
abnormal structure
cells capable of independent growth
spread of cancer and its mechanisms
local spread - surrounding connective tissue
lymphatic spread
blood spread
trans-coelomic spread - across body cavities
common sites of cancer spread
liver, lung, brain, bone, adrenal glands
local effects of cancer
pressure
obstruction
malignant - tissue destruction, bleeding, pain, effects of treatment
systemic effects of cancer
secretion of hormones- normal hormones ( abnormal control of production/secretion), abnormal hormones ( in an organ that doesn’t usually produce that hormone)
weight loss
effects of treatment
concepts of dysplasia and intra-epithelial neoplasia
dysplasia = pre-malignant change
used to indicate the tumour is becoming malignant
identified in epithelium without invasion
neoplasm can become cancerous if left unchecked or untreated
disorganisation of cells
no invasion
early detection of cancer
sensitive/specific testing
acceptable
eg. cervical screening
cell cycle of normal cells
the cell cycle is the interval between mitotic divisions
process of carcinogenesis
production of cancer cells caused by the mutation of genetic material
disrupts cyclin pRB pathway- pRB acts as the cycle brakes, slowing down growth and proliferation, therefore mutation releases the brakes allowing uncontrolled proliferation
P53 pathway- normally maintains genomic integrity stopping cycle when DNA is damaged for repair or apoptosis, mutations prevent cycle from stopping so cell continues despite damage and so mutations occur leading to cancer
major aetiological agents of cancer
heredity/inherited disposition
proto-oncogenes -> oncogene mutations
viruses
chemicals
scientific basis of MRI
magnetic fields make the protons in the body all spin in the same direction
a radio-frequency pulse then distorts the protons and takes pictures by displaying the protons “relaxing” back to their original position
advantages of MRI-specific contrast agents
excellent bone/soft tissue detail
vessels can be demonstrated
cardiac imaging
brain, spine and musculoskeletal system
disadvantages of MRI-specific contrast agents
claustrophobic and noisy
cannot image patient with pacemakers or metal prosthetics/fillings
what is a contrast agents
galdolinium DPTA is an IV medium that causes changed in the magnetic field, altering the tissue signals
vascular lesions and some tumours can be seen ver clearly
very safe agent
