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 as well as chronic inflammation (granulomas)
Macrophages
What is a granuloma?
Organised collection of activated macrophages (ordinary macrophages are phagocytic but when activated, they are also secretory)
What are the 2 most likely causes of granulomas?
Sarcoid
TB
Differentiate the two causes using the acid-fast Ziehl-Neelson stain
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
(Keratin production depends on location e.g. present in skin SCCs but probably not in oesophageal, cervical or lung etc.)
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 or infectious agent and then use stains/detection systems that detect those antibodies
E.g. immunofluorescence, immunoperoxidase
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
Different epitheliums will have different cytokeratin subtypes (e.g. CK20 or CK7) -> helps identify the primary tumour
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)
