Histo: Fundamentals of Histology Flashcards
Describe the appearance of neutrophils.
What does an abunance of them suggest
Multilobed nuclei with lots of granules
Acute inflammation e.g. acute appendicitis
In what states might you seen an abundance of lymphomcytes?
Chronic inflammation e.g. chronic gastritis, but don’t forget possibility of lymphoma if sheets of lymphocytes
WBC on UC biopsy during flare up
lymphocytes and neutrophils
As its an acute on chronic inflammation - this will occur in many chronic inflammatory diseases
Describe the appearance of eosinophils.
Bi-lobed nucleus with red granules
List three conditions that could cause eosinophilia.
Allergic reactions
Parasitic infections - e.g. schisctosomasis
Malignancy - as a reaction to neoplastic process (e.g.Hodgkin’s Lymphoma)
Describe the appearance of the oesophagus in eosinophilc oesophagitis.
Horizontal striae are seen within the oesophagus (feline oesophagus)
likely due to food allergen
Describe the appearance of mast cells.
What does an abundance of them indicate
Large cells containing a lot of granules
Allergic reaction
Describe the appearance of macrophages.
Large cells with lots of cytoplasm
In what states do macrophages tend to appear?
Late in acute inflammation (macrophages clear up the debris)
Chronic inflammation - granulomas are made up of activated macrophages (become secretory rather than phagocytic)
Define granuloma.
Organised collection of activated macrophages.
Describe the appearance of macrophages in granulomas.
Epithelioid macrophages - they have a lot of cytoplasm making them look like epithelial cells (they are secretory rather than phagocytic)
What cytological feature is suggestive of a good sputum sample?
Pigmented macrophages - this suggests that they have come from the alveoli
What do macrophages in granulomas fuse together to form?
Langerhans giant cells
List some causes of granulomas.
- TB
- Leprosy
- Crohn’s
- Fungal infections
- Sarcoidosis
List three types of carcinoma.
- Squamous cell carcinoma
- Adenocarcinoma
- Transitional cell carcinoma
sites of origin of squamous cell carcinoma
What are two key features of squamous cell carcinomas?
Keratin production
Intercellular bridges
normal squamous epithelium also has these features
What are two key features of adenocarcinomas?
Mucin production
Glands
sites of origin of adenocarcinomas
Which stain is used for Melanin?
Fontana stain
What is the difference between a histochemical stain and an immunhistochemical stain?
- Histochemical stain - based on the chemical reaction between the stain and the tissue. The product will have a specific colour or other property that can be identified
- Immunhistochemical - involves using antibodies to detect a specific antigen within the tumour
What type of stain is haematoxylin and eosin?
Histochemical stain - one part will react with the acidic component of the tissue, the other part will react with the basic component
What stain is used for iron?
Prussian blue
Which stain is used for amyloid?
Congo red
When viewed under polarised light, it produces apple green birefringence
Describe the mechanism of:
- Immunofluorescence
- Immunoperoxidase
-
Immunofluorescence
- An antibody will be raisd against a particular antigen
- Another antibody will be raised against the Fc component of the previous antibody, this antibody will be attached to a fluorescence marker
- The first antibody will be to a specific antigen on the tissue and then the second antibody will bind to the first antibody - the flueorscence can then be detected
-
Immunoperoxidase
- An antibody is added to the tissue which binds to a particular antigen
- An enzyme is then added which binds to the antibody
- A substrate is then added which produces a product of a certain colour
What is a key immunological lymphoid marker?
CD45
What is a classic histological feature of HSV infection?
Cells with multiple nuclei
what is the key immunological marker stained for to tell if it is an epithelial tumour
cytokeratin - present in alll epithelium
different numbers for each e.g. CD45
very helpful to tell you what the primary tumour is e.g. if tumour in liver
