Introduction To Pathology Flashcards
What is pathology?
Study of disease & cellular dysfunction
What is dysplasia?
Presence of abnormal cells in a tissue.
May indicate stage preceding development of cancer
What is histology?
Studying a tissue sample under the microscope
What is cytology?
Studying disaggregated (separated) cells under the microscope, usually from a fluid sample
What is the different between histology and Cytology ?
Histology is the study of tissue, Cytology is study of disaggregated cells.
What is a biopsy?
Examination of tissue removed from a living body
- form of histology
Name some examples of histology
- Biopsies
- Endoscopic biopsies
- Cancer resection specimens (surgical removal of tissue)
- Excised skin lesions
Name some examples of cytology
- Using a needle to remove fluid from breast, thyroid, saliva, lung
- cervical smears
- sputum
- urine samples
What is Atypia?
Structural abnormality in a cell
What are 5 advantages and 3 disadvantages of Histology over cytology?
Advantages :
- Therapeutic + Diagnostic
- Can assess architecture + cellular Atypia
- Can differentiate invasive from in situ disease
- Specific - can give information on grade/stage of disease
- Good to use for further tests eg molecular & immunohistochemical
Disadvantages
- Takes longer
- Cost
- involves invasive procedures
What are 4 advantages and 2 disadvantages of cytology over histology?
Advantages
- fast
- cheap
- minimally invasive procedures required
- tests cells in fluid
Disadvantages
- higher error rates
- not entirely diagnostic/specific - only excludes/confirms disease type
What is distension ?
- Outward expansion of abdomen as a result of air/fluid accumulation.
- Usually symptom of underlying disease.
What is ascites?
Accumulation of fluid in peritoneal cavity, causing abdominal swelling.
Name 5 places where serous carcinoma occur?
- ovary
- Fallopian tube
- uterus
- cervix
(Basically the female reproductive organ) - peritoneum
When is cytology best used?
As a preliminary test before histology/other investigations.
When looking at a histology slide, what 4 things should you ask yourself?
- Normal/abnormal?
- Inflammatory/neoplastic?
- Benign/malignant?
- Primary tumour/metastasis?
What is a neoplasm?
Abnormal growth of tissue
What is Coeliac disease?
Common digestive condition where small intestine becomes inflamed and unable to absorb nutrients.
Caused by adverse reaction to dietary protein gluten.
(NHS website)
What type of cells are seen in Hodgkin lymphoma?
Reed-Sternberg cells
What is Adenocarcinoma?
Malignant tumour formed from glandular structures in epithelial tissue
How are the stages of cancer classified?
T - Tumour size (4 stages)
N - nodes involved? (3 stages)
M - Metastasised? (3 stages)
See diagram in lecture
What is Mohs surgery used for?
If cancer is close to margin extra tissue is removed to reduce chance of it reoccurring
If cancer is close to the margin, what does this mean for prognosis?
More likely to grow back (Mohs surgery)
If breast tissue is ER (oestrogen receptor) positive which drug may be used?
Tamoxifen
When may tamoxifen be a suitable drug to use in breast cancer?
If the tissue is ER +ve
When may herceptin be a suitable drug to use in breast cancer?
If tissue is Her2 receptor +ve
Which drug may be used to treat breast cancer in tissue that is Her2 receptor positive?
Herceptin
When does autolysis of tissue begin?
When blood supply is cut off
What do fixatives do ?
Block autolysis of tissue
- denature proteins
- stop bacterial growth
- harden tissue
What is the fixative normally used to preserve tissue?
Formalin /formaldehyde in water
Which agent is usually used to make the tissue hard
Paraffin wax
Describe the process of preparing tissue for examination in histology
- Preserve tissue with fixative (formalin)
- Pathologist cuts up tissue
- Water removed from tissue
- Tissue embedded with paraffin wax to make it hard
- Blocking of tissue makes sample more suitable for slicing
- Sliced into thin sections with microtone 3-4 microns
- Stained with haematoxylin & eosin
- Mounting preserves the tissue on the slide
Tissue ready to be examined !
Which enzyme is used in immunohistochemistry and how what useful property does it have?
Peroxidase
Catalyses a colour producing reaction
What colour substance is formed with use of peroxidase?
Brown
What type of substances can be identified using immunohistochemisty, give some examples ?
Any substances that are antigenic (have antigens on them)
- actin protein to determine if smooth muscle present on the tissue being examined
- Cadherins - cells adhesion molecules - absent in some carcinomas
- Receptors - ER, HER2 receptor
- Microorganisms
- cytokeratins: if present cancer = carcinoma (epithelial origin)
What are cadherins and why are they useful to test for on tissue biopsies?
- cell adhesion molecules
- help determine type of cancer as absent in some types of carcinomas
What are cytokeratins and why are they useful to test for on tissue biopsy?
Fibrous proteins present in all epithelial cells
- if present on cancer tissue can be used to determine which epithelia the carcinoma originates from.
The immunohistochemistry results show:
CK7+/CK20-
Which type of epithelia may this tissue have come from?
Thyroid Lung Breast Ovary Endometrium
What is the endometrium?
Inner epithelial layer of uterus
The immunohistochemistry results are:
CK7-/CK20+
Which type of carcinoma may this tissue be?
Large bowel carcinoma
Gastric carcinoma
Before treating with the drug Herceptin what is the name of the receptor that should be present in the cancer tissue?
What tests can be used to determine if the receptor is present or not?
- Her2 receptor = A growth factor receptor
- immunohistochemistry & FISH (used to test for the Her2 receptor gene)
Mutations in the EGFR (epidermal growth factor regulator) gene suggests which type of cancer?
Lung
What is the drug erlotinib and what is it used for ?
- An Anti-EGFR (epidermal growth factor regulator)
- Lung cancer
What is the difference between testing for a gene using FISH and testing mRNA?
FISH - tells you if gene is present on a chromosome
Testing mRNA - tells you if gene is actually being transcribed
What is a tumour and what could it be?
Swelling
Can be inflammation or neoplasm
Neoplasm can be malignant or benign
What is a frozen section/cryosection & how accurate is it?
Procedure used to perform rapid microscopic analysis of a lesion obtained from surgery. Result influences the course of the operation.
96% accuracy
What type of cancer can radiology cause?
Angiosarcoma (cancer of inner lining of blood vessels)
