Fundamental of Histology Flashcards
Neutrophils
morphology
associated with
example of condition
granulocytes with multilobed nuclei
acute inflammation
acute appendicitis (wall of crypt in inflamed appendicitis)
Lymphocytes and plasma cells
morphology
associated with
condition
round, very alrge nucleus, very little cytoplasm
chronic inflammation
IBD = acute-on-chronic disease
- neutrophils and lymphocytes
- flare up = acute on chronic picture
Lymphoma appearance
what condition/infection is associated with lymphoma
sheets of lymphocytes amongst macrophages (‘starry sky’)
cells are uniform (clonal proliferation)
H. pylori gastritis
Multiple myeloma
if you see sheets of plasma cells (seen in autoimmune diseases e.g. rheumatoid arthritis) it could indicate multiple myeloma
Eosinophils morphology
associated with
condition (2)
Bi-lobed, bright red granules
allergic reactionsm, parasitic infections and tumours (Hodgkin’s)
In Hodgkin’s, the eosinophilia is a reaction to the neoplastic process (not the malignant cells)
Eosiniophilic oesophagitis = horizontal striae (feline oesophagus), this is an allergic reaction to consumed antigen (common in children)
Mast cells morphology
what do the granules containe
degranulation is associated with
large and very granulated
contain many different inflammatory mediators
associated with urticaria (bopsy of the skin shows many mast cells)
Macrophages mrophology
associated with
natural state vs chronic inflmamation
condition
lots of cytoplasm
late acute inflammation, chronic granulomatous inflammation
natural state = phagocytic, chronic inflammation = secretory
TB = caseous necrosis in lung
Granuloma
granulomatous macrophages morphology
what can you sometimes see
organsied collections of activated macrophages
activated to become secretory
lumps aka granulomas
morphology = lots of cytoplasm (look like epithelial cells) so sometimes called ‘epithelioid macrophages’ specialised for secretion
you sometimes see Langerhans giant cells (the ring-shaped structure at the bottom)
Causes of granulomas
tuberculosis
leprosy
cat-stratch fever (from cats licking an open wound)
fungal infections
sarcoidosis (idiopathic granuloma)
if a granuloma is seen in a lymph node/lung, what do you do?
use ZN stain to check for acid-fast bacilli (TB)
Sputum samples and macrophages
what can you see
difficult to obtain (if from lungs or upper airway)
pigmented macrophages in sample shows that the sample has come from the alveoli and it is a good sample
macrophages in lungs are pigmented because they phagocytose all the inhaled debris
4 types of tumours
features of tumour cells (3)
types:
- carcinoma (malignant epithelial)
- sarcoma (bones and soft tissue)
- lymphoma (lymphocytes)
- melanomas (melanocytes)
Large and irregular nuclei
Increased and abnormal mitoses
Increased nucleo-cytoplasmic ratio (nuclei bigger than normal)
SCC
2 main features
locations
keratin production (whirls of keratin at center), intercellular bridges
skin, head and neck, oesophagus, anus, cervix, vagina
Adenocarcinoma (glandular epithelium)
location
what can you see in stain
morphology
glandular epithelium (lung, breast, stomach, colon, pancreas)
mucin within gland, goblet cells
nuclei are dark and multi-layered
Transitional cell carcinoma
where
urinary system
melanomas
how to confirm
what stain
melanocytes
biopsy
small % will NOT secrete melanin (amelanotic melanomas) as so poorly differentiated
Fontana stain
2 types of stain
histochemical
immunohistochemical
3 types of histochemical stains
immunofluorescence vs immunoperoxidase
How can we tell the type of carcinoma (histology in practice)
cytokeratin antibody (IFs, a characteristic of epithelial oriign)
if no cytokeratin, then the cell is NOT of epithelial origin
even when carcinomas are poorly differentiated, they will make cytokeratins (ALL epithelial cells have cytokeratin)
there are antibodies against different cytokeratins (e.g. CK7, CK20)
depending on the types of cytokeratins that are present within the tumour, you can figure out which type of carcinoma it is
Differentiating between a carcinoma and a lymphoma
using monoclonal antibodies to identify infectons (herpes simplex)
