Tumour Pathology Flashcards
What is a tumour?
A tumour is an abnormal mass of growing tissue
Describe tumour growth.
Growth is uncoordinated with that of the surrounding tissue and continues after the removal of any stimulus which caused it.
What are the two types of tumour?
Benign
Malignant
What is the difference between benign and malignant tumours?
Malignant tumour is able to metastasise and spread throughout the body.
What characterises a benign tumour?
- Non-invasive growth pattern
- Usually encapsulated
- No invasion/metastases
- Cells similar to normal- well differentiated
- Function similar to that of normal tissue
- Rarely cause mortality- unless in bad place (brain/heart etc)
What characterises a malignant tumour?
- Invasive growth pattern
- No capsule/or capsule is breached by tumour cell
- Cells are abnormal- poorly differentiated
- Loss of normal function- spread of cancer
- Frequently cause death
Which type of tumour is cancer?
Malignant
Which type of tumour frequently causes death?
Malignant
What is tumour nomenclature based on?
The tissue of origin and whether or not it is malignant.
What are tumours called in glandular epithelium?
Benign = Adenoma Malignant = Carcinoma
What are tumours called in squamous epithelium?
Benign = Squamous papilloma Malignant = Squamous carcinoma
What are tumours called in the bone?
Benign = Osteoma Malignant = Osteosarcoma
What are tumours called in the fat?
Benign = Lipoma Malignant = Lipo-sarcroma
What are tumours called in the fibrous tissue?
Benign = Fibroma Malignant = Fibro-sarcroma
What is cancer called in the blood?
Only WBC, only malignant = Leukaemia
What is cancer called in the lymphoid tissue?
Only malignant = Lymphoma
What are tumours in the melanocyte tissue called?
Benign = Naevus Malignant = Melanoma
What are tumours in neural tissue called?
CNS = Astrocytoma PNS = Schwannoma
What are tumours in germline cells called?
Teratomas- develop in gonads, composed of various tissues.
What are the properties of cancer cells?
- Loss of tumour suppressor genes
- Gain of oncogene function
- Altered cellular function
- Abnormal morphology
- Capable of independent growth
- Tumour biomarkers
Why do cancer cells lose the tissue function?
Loss of cell-to-cell adhesion
Altered cell-to-matrix adhesion
Production of tumour-related proteins including tumour biomarkers.
What are tumour biomarkers?
Tumour biomarkers are biochemical indications of tumour development and progression.
Why are tumour biomarkers utilised clinically?
To allow diagnosis- used in screening, prognosis and prediction.
What is alpha-fetoprotein a tumour biomarker for?
Teratomas of testes (testicular cancer) Hepatocellular carcinoma (liver cancer)
What is carcinoma-embryonic antigen (CEA) a tumour biomarker for?
Colorectal cancer.
What is oestrogen receptor a tumour biomarker for?
Breast cancer.
What is prostate specific receptor a tumour biomarker for?
Prostate cancer.
What is kRas?
Biomarker for colorectal cancer.
What is Braf?
Biomarker for melanoma.
What are EGFR/PD-L1
Biomarkers for lung cancer.
What is HER2?
Biomarker for breast/gastric cancer.
What does tumour morphology exhibit?
Cellular and nuclear pleomorphism (marked variation in shape and size)
What is tumour growth based on?
A balance between angiogenesis and apoptosis (new blood vessel formation and death).
What is angiogenesis?
Angiogenesis is the formation of new blood vessels by tumours. It is required in order to sustain tumour growth and provides a route for tumours to enter into the circulation. More blood vessels in a tumour leads to a poorer prognosis due to faster spread.
What is apoptosis?
Programmed cell death, active cell process which regulates cell growth, utilised in chemotherapy and radiotherapy,
What is metastases?
Spread of cancer leading to the formation of secondary tumours.
How does tumour invasion work?
It is a multi-step process with increased matrix degradation by proteolytic enzymes. There is altered cell-to-cell adhesion and cell-to-matrix adhesion.
What are the modes of cancer spread?
Local spread
Lymphatic spread
Blood spread
Trans-coelomic spread