Fundamentals of histology Flashcards
Neutrophil infiltration
Acute inflammation
Lymphocyte / plasma cell infiltration
Chronic inflammation
Neutrophil + lymphocyte / plasma cell infiltration
Acute-on-chronic inflammation
Differential for sheets of lymphocytes
Chronic inflammation
Lymphoma
Multi-lobar (2-5) nucleus
Pink on H+E stain
Granular cytoplasm
Neutrophil
Granules stain red with eosin (high affinity for acid)
Romanowsky method
Eosinophils
3 causes of eosinophilia
Allergic reaction
Parasitic infection
Hodgkin’s lymphoma
Feline contraction
‘Asthma of the oesophagus’
Eosinophilic oesophagitis
Raised in allergic reactions
Granules contain histamine + heparin
Mast cells
Appear late in acute inflammation + form granulomas
Specialise in different tissues (e.g. Kupffer cells in liver)
Derive from monocytes
Macrophages
Bi-lobed nucleus
Eosinophil peroxidase + ribonuclease granules
Eosinophil
How do you know if a sputum sample is superficial or deep?
Presence of macrophages - alveolar macrophages deep in lungs so if present know it is a good sample. May be black from phagocytosis of pollutants
Macrophage cluster
Macrophages = ‘epithelioid’ as look like epithelial cells + elongated nucleus
Granuloma
Caseating granuloma
Dark patches of cell necrosis with loss of cell nucleu
TB (most common), leprosy, fungal, histoplasmosis, cat scratch disease
Non-caseating granuloma
No necrosis
Sarcoidosis, Crohn’s
Most common cause of casating granuloma
Acid-fast bacilli on Ziehl-Neelson stain
TB
Intercellular bridges
Keratin
Squamous cell carcinoma
Mucin production
Glands
Adenocarcinoma
Fontana stain for melanin
Melanoma
Malignant epithelial cell tumour
Carcinoma
Cytokeratin
Epithelial cell marker
CD45
Lymphoma marker
CK20+CK7-
Large bowel cancer primary tumour
2 types of stain
Histochemical (e.g. H+E - chemical reaction)
Immunohistochemical (bind to specific antigens)
Positive / basic, binds DNA and RNA
Haemotoxylin
DNA / RNA are negative + acidic
Negative + acidic, binds protein
Eosin
Proteins have positive a.a. side chains
Prussian blue stain
Haemochromatosis
Brown on H+E staining
Iron
Congo red stain
Apple green birefringence under polarised light
Amyloidosis
