Histopathology and cytopathology [Complete] Flashcards
What is histopathology?
Preperation and examination of tissue sections
Where can tissues be collected?
Biopsies
Resection specimens (Cut tissues or part of organs such as intestine)
Frozen section
Post-mortems
What is cytopathology? How does this differ to histopathologists?
Examination of individual cells
Histopathologists examine tissues
How may cytopathologists collect cells?
Smears
Fine needle aspirate
What situations would require the use of histo and cytopathology as a diagnostic method?
Tissue diagnosis e.g. cancer spread and staging
What are the purpose of biopsies?
Check for normality
Inflammation
Cancer and type
What are resection specimines?
Taking out large sections of organs to look at cancer’s interaction with blood vessels and other structures.
Basically check for mestateses
What are frozen sections and what is their purpose?
Sample sent to a lab during an operation.
Frozen, sliced, stained and examined ASAP (Rapid diagnosis)
They are used to indicate whether the margins are clear of cancer. If not then surgeons need to remove more of the tissue/organ
When might frozen section diagnosis be required?
To tell if all of a tumor is removed
To tell if something is cancerous
To identify abnormalities during another operation and deal with them if needs be e.g. c-sections often find abnormalities that need to be tested.
What are the advantages of frozen section diagnosis?
Rapid diagnosis
20-30 mins
Can prevent multiple surgeries and fully remove tumor/deal with a problem quickly.
What type of specimens might be tested?
Histopathlogy 1) Biopsies of tumors 2) resection specimens 3) frozen sections Cytopathology 1) Smears -HPV screening 2) Fine needle aspirates
What are the main steps in processing a specimen?
Label properly with patient details
Fix in formalin to fix tissue in place
Embed in paraffin wax
Cut sections
With sections you can:
Stain: e.g. gram staining, Ziehl–Neelsen stain
Identify specififc antigens (using antibodies)
Perform molecular tests
How long does it take for histopatholigists to send results based on the type of investigation performed?
What are fine needle aspirates?
Usually fluids e.g. from a lump in the neck.
Can take soild samples and suspend them in liquid. Used for cytology
What can immunohistochemistry reveal?
What can CD31 show?
Markers for lymphocytes, breast cells, vessels ect.
CD31 indicates vascular tumor infilltrating collagen bundles
