Histopathology 1 - Fundamentals of histology Flashcards
What type of cell is predominant in the inflammatory process in acute appendicitis/gastritis/mastitis?
Neutrophilic inflammation
What are the 4 main causes of eosinophilia?
- Allergic reactions
- Parasitic reactions
- Tumous eg Hodgkin’s disease (not a neoplasm of eosinophils but a reaction to the neoplastic process)
- Eosinophilic granulomatosis
If ‘feline contractions’ are observed in the oesophagus, what is the pathology?
Eosinophilic oesophagitis - probably due to a food allergen (“asthma of the oesophagus”)
Which cells are most associated with LATE acute inflammation and granulomas
Macrophages
What is a granuloma?
Organised collection of activated epitheloid macrophages
What are the 2 most likely causes of granulomas?
Sarcoid
TB
What is a carcinoma?
Malignant tumour of epithlial cells
What are the 2 key histological features of a squamous cell carcinoma?
Keratin production
Intercellular bridges
*do not form glands
What are the 2 key histological features of an adenocarcinoma?
Mucin production
Glands
What is the basic principle of how immuno-histochemistry works?
Use an antibody to a particular antigen in a tumour and then use stains that detect those antibodies
How do histochemical stains work?
Chemical reaction between chemicals added in the stain and the tissue that causes a change in colour
What is used to stain amyloid?
Congo red stain
How does amyloid appear under polarised light?
Apple green birefringeance
Which polymorphs have a bilobed nucleus?
Eosinophils
What is cytokeratin a marker of?
Epithelial cells - so can identify carcinomas
What is CD45 a marker of?
Lymphoid cells - so can identify lymphomas
What stain can be used to detect melanin?
Fontana
What stain can be used to detect iron (eg in haemachromatosis)?
Prussian Blue (think Prussia hated on both sides of IRON curtain)
3 histochemical stains
- fontana stain: +ve for melanin
- congo red: amyloidosis
- prussian blue: iron (haemachromatosis)
Immunohistochemical stains
CD45: +ve for lymphoid cells
Cytokeratin: epithelial marker
which cell is this and its role
neutrophils
Multilobe cells that are granulates
Associated with ACUTE inflammation i.e. acute appendicitis, salpingitis
what cell is this and what can conditions can this cell be aberrant in
lymphocytes
- Key inflammatory cells of CHRONIC inflammation
- There are tumours of lymphocytes- lymphomas.
Whhich cells are these
Eosinophils
which cells are these
Mast Cells
Large cells containing lots of granules with range of inflammatory mediators
involved in allergic reactions
**they are bigger than basophils and more purple
which cells are these and what type of inflammations are these associated to
Macrophages- large cytoplasm
associated with late acute inflammation and chronic inflammation
what does this show
Granulomatous Inflammation with surrounding lymphocytes
what are giant cells and whatc condition are they usually seen in
- formed by the fusion of macrophages.
- They are characteristic e.g. in TB (Langheran’s giant cells).
which stain is used to diagnose TB
Zeihl-Neelson stain
list what tumours these are:
carcinoma
sarcoma
osteoma
osteosarcoma
Carcinomas- malignant tumours of epithelial cells.
Sarcomas- malignant tumours of mesenchymal cells e.g. connective tissue (muscle, bone, cartilage
Osteoma- benign tissue of bone
Osteosarcoma- malignant tissue of bone
Summaryof the main stains
