Pathology Flashcards
What are Koch’s postulates?
Criteria to establish a causative relationship between microbe and disease
What are some controllable and uncontrollable risk factors for atherosclerosis?
Uncontrollable - age, family history, being male
Controllable - hyperlipidaemia, hypertension, smoking, diabetes
Which HLA genes cause:
a) ankylosing spondylitis
b) Graves’ disease
c) coeliac disease
d) insulin-dependent diabetes
e) rheumatoid disease
a) B27
b) DR3
c) DR3
d) DR3/DR4
e) DR4
Name 3 microscopic features of cell damage
swollen ER and mitochondria
Chromatin clumps
Membrane blebs
Which enzyme triggers apoptosis?
Caspase 3
What is the difference between intrinsic and extrinsic apoptosis?
Intrinsic - due to cell damage cell dies it should die
Extrinsic - cell recognised that cells around it are dying so it probably should too
What is:
- Atrophy
- Hypertrophic
- Hyperplasia
- Metaplasia
- Decrease in cell size or number of cells
- Increase in cell size
- Increase in cell number
- One adult cell type changes to another
What are the two types of pathological calcification?
Dystrophic - associated with necrosis, serum Ca2+ is normal
Metastatic - associates with hypercalcaemia, no tissue damage but increased bone destruction e.g. due to paraneoplastic syndrome
Give some features of benign neoplasms.
Slow growth rate Few mitotic figures Well differentiated Often normal nuclei Circumscribed / encapsulated Do not invade Do not metastasise
Give some features of malignant neoplasms.
Rapid growth rate Numerous mitotic figures Variable differentiation Hyperchromic - dark nucleus Pleomorphic nuclei -variation in size and shape No capsule, often ill-defined border Invasive Frequently metastasise
What is a benign neoplasm of cartilage called?
Chondroma
What is a malignant neoplasms of blood vessels called?
Angiosarcoma
What is a malignant striated muscle tumor called?
Rhabdomyosarcoma
What is a seminoma?
Malignant testicular neoplasm
What is a teratoma?
Difference between the two types.
Germ cell neoplasm.
Testes - malignant and do not differentiate.
Ovary - benign and differentiate a lot.
Name an infectious cause of Hodgkin’s lymphoma
Epstein-Barr virus
Which type of cancer tends to spread through lymphatics?
And which ones through haematogenous routes?
Lymphatic - carcinoma not sarcoma
Haematogenous - sarcomas AND carcinomas
Which immunohistochemical stains are used to test for
- Intermediate epithelial filaments
- Neural crest markers
- Cytokeratin
2. S100
Difference between grade and stage of tumour?
Grade - degree of differentiation, done by histological assessment
Stage - extend of spread, done by clinical/radiological assessment and lymph node histopathology
What are the stages of CIN?
CIN1 - mild dysplasia, confined to basal 1/3 of epithelium
CIN2 - moderate dysplasia confined to basal 2/3 of the epithelium.
CIN3 - severe dysplasia with undifferentiated neoplastic cells spanning more than 2/3 of the epithelium. May also involve carcinoma in situ.
What is the difference between an oncogene, a proto-oncogene and a tumour suppressor gene?
Oncogene - mutated/activated gene which contributes positively to neoplasia. Dominant acting.
Proto-oncogene - aka cellular oncogene, is the unaltered non-mutated cellular counterpart of an oncogene
Tumour suppressor gene - a gene which normally functions in a manner which inhibits neoplasia. Recessively acting.
Which fungal toxin is found in some peanuts and what cancer does it predispose to?
Aflatoxin
Liver cancer - hepatocellular carcinoma
Which carcinogen is found in fossil fuels, animal fat and tobacco?
How does its pathophysiology explain why some smokers never get cancer?
Polycyclic aromatic hydrocarbons.
Are converted into an active carcinogens by oxygenases, and genetic variation in these enzymes leads to different susceptibility.
What are aromatic amines and azo dyes and describe their metabolism in the body, and the cancer they cause?
They are:
Hydroxylated in the liver which activates them, then conjugated in the liver which deactivates them.
Then they are deconjugated in the kidney which reactivates them.
This therefore causes bladder carcinomas.
How does UV radiation cause skin cancer?
UV crosslinks pyramidine bases (cytosine and thymine) which is usually repaired, but excessive damage overwhelms the repair pathway leading to mutation.
Can cause melanomas, squamous cell carcinomas and basal cell carcinomas.
What are the viral oncogenes used by Epstein Barr virus?
Latent membrane protein 1 and 2 - mimics cell signalling receptors and hijacks growth-promoting signalling pathways
EBNA-2 - functions as a transcription factor to upregulate growth
What is Rb (retinoblastoma) and how does it work?
What is its role in neoplasia?
Rb controls E2F by binding to it and keeping it inactive.
When growth is required, cyclin D levels increase and cycin D phosphorylates Rb, hence preventing it from binding to E2F and hence driving the expression of genes and the cell cycle.
Dysregulation of this process can lead to uncontrolled cell division.
This process disrupts the G1–>S checkpoint
What is the APC gene and how does it work?
It is the adenomatous polyposis coli gene. It inhibits the cell growth signalling pathway in the colon.
What is familial adenomatous polyposis (FAP)?
What is the genetic basis of this condition?
A huge amount of polyps across the whole colon.
It is caused by germline APC mutations.
All patients with this condition get a prophylactic panproctocolectomy at age 25 as the polyps can become cancerous.
APC is a tumour suppressor gene but this condition acts in an autosomal dominant way as the “second hit” occurs very easily.
What is Li Fraumenti syndrome?
Germline p53 mutation
What is hereditary non-polyposis colorectal cancer syndrome? (HNPCC)
No polyps.
Germine defect in 1 allele then sporadic defect in second allele coding for mismatch repair proteins.
Leads to colorectal tumours, endometrial and ovarian tumours.
What are some causes of chronic gastritis?
The causes are ABC
A - autoimmune e.g. autoantibodies against parietal cells which leads to destruction of the K+/H+ pump and loss of intrinsic factor which leads to perinicious anaemia.
B - bacterial - H pylori
C - chemical e.g. bile+bicarb, gallstones etc
What are some consequences of chronic gastritis?
Eventually leads to atrophic gastritis.
This can lead to intestinal metaplasia due to increased acid secretion, which predisposes to adenocarcinoma.
Or a carcinoid tumour can form due to ECL cell hyperplasia.
What is an ulcer?
It is a breach in the GI wall FUTHER THAN the muscularis mucosae.
What are the two types of peptic ulcers? Explain differences between them.
Gastric ulcer - has normal/low acid, affects older people.
Duodenal - normal/high acid and affects younger people
What are some causes of acute oesophagitis?
Candida, herpes
What are some causes of chronic oesophagitis?
Main cause is reflux.
Other causes are Chron’s disease and TB.
Name some hallmark features of Chron’s disease?
Fissuring ulcers Strictures Discontinuous inflammation affects whole GI tract Granulomas Low malignancy risk Transmural inflammation
Name some hallmark features of ulcerative colitis?
Toxic megacolon Limited to colon Continuous / pancolitis Inflammation confined to mucosa Pseudopolyps High malignancy risk
Describe the transmission of Hepatitis A-E
A - faecal-oral, shellfish, polluted water B - blood borne C - blood borne D - blood borne E - uncooked pork products
Name some causes of acute and chronic hepatitis?
Acute - hep A, hep E, CMV, EBV
Chronic - hep B, hep C, hep D
