4: Histo/Cytopathology Flashcards
What do histopathologists and cytopathologists work on?
Histo = TISSUES
Biopsies, resection specimens from surgery, frozen sections (real-time diagnosis), post-mortems
Cyto = CELLS
Smears and fine needle aspirates
What can you do with different histopathology samples?
Biopsies - from moles, lumps, polyps.
Helps narrow down diagnosis + defines how you treat patient
Resection specimens - Removing tumour and analysing big part of tissue. Determines SPREAD OF CANCER
Frozen sections - Determine spread and type of cancer (e.g. mid-operation)
Post-mortems
HOSPITAL pm = family give consent after doctors’ request. Can be for research/improvement of techniques
CORONER’S pm = State official. No consent needed
How are sections obtained?
- Specimen properly labelled
- Fix in formalin (fixative)
- Embed in paraffin wax
- Cut thin sections
What do you do with sections?
- Stain (e.g. gram)
- Immunohistochemistry - look for specific cancer markers
- Carry out molecular tests
What is cytopathology?
Looking at CELLS not tissue
Fine needle aspirations - Take fluid from abnormal tissue/lump/body fluid and look at cells under microscope
Also used for cervical screening (cervical smear test looking for HPV)
How long do different types of histopathology results take to reach clinician?
Frozen section -> 30 mins
Biopsies -> 2-3 days
Resection specimens -> 5-7 days
Kaposi’s sarcoma is defining diagnosis of?
HIV AIDS
You would see proliferating blood vessels on biopsy of skin
Immunocytochemistry for CD31 in Kaposi’s sarcoma shows?
Vascular tumour infiltrating collagen bundles
CD31 is a marker for vascular endothelium
What type of cytopathological test would you use to check enlarged lymph nodes?
Fine needle aspiration
Fine needle aspiration of lymph nodes showed a mixed cell population. What does this indicate?
NOT cancer since its mixed cells, it is probably just REACTIVE lymphadenopathy (i.e. activated lymphocytes in response to infection)
