CA1: Non-neoplastic and neoplastic changes Flashcards
Define atrophy
A wasting or decrease in size
Give examples of physiological atrophy
Atrophy of remnant structures during development e.g. thyroglossal cyst which is an embryological growth that should disappear
Muscle atrophy after stopping weight training
Give examples of pathological atrophy
- Cardiac
- Malnutrition
- Hair follicles with age
- Alzheimer’s disease which is secondary to brain atrophy where gaps develop between sulci
Define hyperplasia and explain where this can occur
Increase in cell number but not cell size - this occurs in organs which have proliferative capacity and stem cells
Give examples of physiological hyperplasia
Endometrium - hyperplasia and then shedding in menstrual cycle
Thyroid hyperplasia due to lack of iodine (this can block the larynx and cause death)
Give examples of pathological hyperplasia
Lymph node reaction to viral infection; EBV glandular fever
Hyperplasia of prostate with age
What are the complications associated with hyperplasia
It can cause obstruction and so infarction, or over-secretion of hormones
Define hypertrophy
Increase in size due to increase in cell size - the cells dont divide as they dont have the proliferative capacity and so cannot regenerate
Give examples of hypertrophy
Athletes muscles and the heart - this can cause cardiomayopathy where there is obstruction due to narrowing in the heart as a result of increased muscle causing subendocardial MI
What is metaplasia
Change from one fully mature tissue type to another fully mature tissue type
Outline the different types of metaplasia
- Squamous to glandular = Barrett’s oesophagus
- Glandular to squamous = in bronchi due to smoking
- Stomach to intestinal type = stomach acid reflux
How does metaplasia lead to neoplasm
Metaplasia is not pre-neoplastic but it may go on to cause dyspladia which will cause neoplasm
Describe the appearance of cells in dysplasia
- Pleomorphic = multiple different shapes
- Increased mitosis
- Disorganised
What is dysplasia
The premalignant changes causing atypia in epithelium
There is no invasion into the basement membrane
What is an adenoma
Benign glandular tumour
What is an adenocarcinoma
Malignant glandular tumour
What is squamous cell carcinoma
Malignant
What is squamous cell papilloma
Benign
Why do tumours arise in epithelia
Because these are areas of high proliferation; most common -
Breast Prostate Bowel Lung Skin
Outline the pathogenesis of cancer in a smoker
Smoking causes bronchi irritation Metaplasia from glandular to squamous epithelium Continued smoking causes DNA changes Dysplasia More DNA changes Invasive cancer
How is proliferation in tissues regulated
Cell division and apoptosis
How do abnormally switched on genes cause cancer
Normal proto-oncogenes can be switched on to give oncogenes when abnormal and these cause cancer
How do abnormally switched off genes cause cancer
When tumour supressor genes are turned off e.g. P53 meaning that damaged cells will not apoptose
What is HPV and what does it cause
Human Papiloma Virus causes cervical cancer
- introduces DNA into cells which interferes with gene function
- inactivates tumor supressor gene so no p53 produced
How can hepatitis B cause cancer
It is a DNA virus which causes long term cirrhosis of the liver on infection - the fibrous nodules formed can undergo cancerous changes, leading to hepatocellular carcinoma
